Browning of corals

[chrisfraser05]

This is a new one on me but bear with me....


I run an algae scrubber and my nitrate and phosphate is 0.

The tank has been running in one form or other since jan this year and has been completely skimmerless since about june.

Now I've had NO problems with nit or phos relating to the scrubber or lack of skimmer, infact I would NEVER be without one!

my corals are growing like mad and I'm really really happy.

One think I can note is that although some of my sps are pretty bright green and orange, everything else seems a little duller that I expect.


Now.... I was speaking to someone who runs over 30,000 lt of systems and has nearly £250,000 worth of stock, corals and fish (self owned retailer) and he was quite positive about algae scrubbers :)

He did however say that in a closed system he wouldn't advise running without a skimmer. He claimed that high level of protiens, like in a skimmerless scrubber system, the high level of protiens would cause browning of corals.

Is this true and is this why my corals are pretty dull although they do grow well!!!

Just putting it out there!

Chris

[Ace25]

The advice you were given sounds reasonable to me. Although one small thing I disagree with is the export method used to remove the proteins. A skimmer will do it, but only about 30% efficient, where as a simple mesh bag of Rox 0.8 carbon will remove over 80%. On one system I use a skimmer with my ATS, on the other system which is only around 6 months old, I was only using an ATS and it did great, but I just started noticing some issues with my SPS corals so I tossed in a small bag of Rox Carbon and the corals are getting happy again. I think it was a gradual build up over time, so now I think I am going to add "toss is a small bag of Rox carbon for a weekend once a month" to my maintenance routine instead of running a skimmer all the time.

[chrisfraser05]

I may shove my nano skimmer in the sump then, its massively "undersized" for the tank but might just keep the protiens down a little.

[SantaMonica]

Proteins (DOC) do not cause browning; inorganics do. And skimmers do not remove inorganics.

Although you might not measure any "standing stock" of nutrients, they are still there, flowing rapidly like a river from decaying food/waste into your scrubber. And they are passing by your sps on the way. So the sps are actually getting more nutrients than you think. It's just that your scrubber removes the nutrients so fast that you can't measure them.

Two solutions: Scrub harder, and/or, have a higher throughput to your scrubber. The faster that you can get water from your display to your scrubber, the less time the nutrients will have to effect anything. This is where wide high-gph scrubbers have an advantage: getting watter from the display to the scrubber as fast as possible.

This brings up a related point, that measurable "standing stocks" of nutrients are really not of much value. "Flux" is the real value of interest. It the same as comparing voltage to current: Voltage is the measurable "standing stock"; Current is the flux into the scrubber. Although the "voltage" may be low, the "current" of nutrients is very high, and can cause problems if it passes nearby something sensitive (like sps).

[Ace25]

What I have been taught is that zooxanthellae is naturally brown in color, when you have to much DOCs in the tank (food), you end up over feeding the zooxanthellae, which then multiply much more in the coral and why corals get the "brown" look. I could be wrong and all the information I have read and been told is false.. but I do feel pretty confident that excess DOCs in a tank can be one reason why SPS corals brown out.

http://en.wikipedia.org/wiki/Zooxanthella

Zooxanthellae are flagellate protozoa that are golden-brown intracellular endosymbionts of various marine animals and protozoa, especially anthozoans such as the scleractinian corals and the tropical sea anemone.

I thought skimmers did remove inorganics? AA seems to think so.
http://www.advancedaquarist.com/2010/2/aafeature

An interesting and perhaps unanticipated observation is that only 34% of this solid skimmate material can be assigned to "organic carbon", TOC. Thus, 2/3 of the solid, water-insoluble part of the skimmate is not TOC, but rather inorganic material that may (or may not) have biogenic origins. If a substantial amount of this inorganic material does come from the shells of plankton, then it stands to reason that a large part of the detected organic material (TOC) probably constitutes the "guts" of these organisms. Thus, perhaps not that much of the TOC removed by skimming is actually free-floating organic molecules.

Only a minor amount of the skimmate (solid + liquid) could be attributed to organic carbon (TOC); about 29%, and most of that material was not water soluble, i.e., was not dissolved organic carbon. The majority of the recovered skimmate solid, apart from the commons ions of seawater, was CaCO3, MgCO3, and SiO2 - inorganic compounds!

[kerry]

Now I am way confused!!! If the inorganic is bound to the organic I can see the skimmer removing it. Well maybe??? This is making my head hurt!!!!

[chrisfraser05]

its always good to open up a debate lol.

My scrubber up to now has been doing a cracking job keeping the water clean in terms of nitrate and phosphate and the corals all seem healthy if a little dull in colour.

I have to say I'm not 100% happy with my scrubber flow but I had to make a compromise when moving the scrubber into the sump cabinet and flow suffered as a result.
I believe that I've still got sufficiant flow and my params tell me so but I'm increasing it soon.

Problem is my pipe size was something not readly available in my local area so I had to wait to get the right bits. I've got them now and will be turning my entire overflow pipework into a scrubber feed :)

My return pump is putting about 4000lt an hour into the tank taking into account head height (ehiem 5000+) so this will effectively double my current flow I reckon.

I'm on a course at the moment so will be doing this when I get back in a couple of weeks.

I'll see if over a few months the corals colour up any more before looking at refitting an under sized skimmer and testing that theory too.

Chris

[SantaMonica]

when you have to much DOCs in the tank (food), you end up over feeding the zooxanthellae

Zoox do not eat DOC; they eat inorganics. Not to mention, that DOC is very high in the ocean, and, is where almost all the carbon is sequestered.


The majority of the recovered skimmate solid, apart from the commons ions of seawater, was CaCO3, MgCO3, and SiO2 - inorganic compounds!

We are not concerned with abiotic inorganics; only ammonia/ammonium, nitrite, nitrate, and phosphate, which are not removed by skimmers.


If the inorganic is bound to the organic

That is called food. Ever eat an apple? It is phosphorus bound to carbon, otherwise known as food. You have a pet dog? He is made of phosphorus bound to carbon.

Skimmers remove organics, algae remove inorganics.

[Ace25]

Zoox do not eat DOC; they eat inorganics. Not to mention, that DOC is very high in the ocean, and, is where almost all the carbon is sequestered.
Here is a simple source but factual. Maybe it isn't the zoox eating the DOCs directly, but rather the coral absorbing the DOCs which then lead to a happier environment for zoox to multiply. Either way I still feel excess nutrients and rapid changes in light spectrum/intensity are the 2 most common reasons why SPS corals "brown out". http://saltaquarium.about.com/cs/coralc ... 021603.htm (http://saltaquarium.about.com/cs/coralcare/a/aa021603.htm)

The fourth category of food utilized by corals is Dissolved Organic Material (DOM) which is absorbed across cell membranes directly into the coral.
And if you don't fix the nutrient problem, it can lead to coral bleaching.. like a city that gets too crowded and then all of the sudden everyone decides to move away all at once.
http://www.science.org.au/nova/076/076print.htm

excess nutrients such as ammonia and nitrate from fertilisers and household products entering the reef ecosystem. (The nutrients might increase the number of zooxanthellae in the coral, but it is possible that the nutrient overload increases the susceptibility of coral to diseases.)

[dtyharry]

Zoox do not eat DOC; they eat inorganics. Not to mention, that DOC is very high in the ocean, and, is where almost all the carbon is sequestered.[/quote]
I think it is important to clarify the statement 'doc is very high'. Yes in terms of total mass there is a lot of organic carbon. The oceans are estimated to weigh 1374 million billion tonnes and so if we take an average figure of one part per million doc that it is a lot! However , it is still a tiny fraction, think about it, one part organic carbon, 999999 parts water. Yes, over reefs it is slightly more than 1ppm but not much more. In an aquarium this amounts to a tiny amount of doc, 1ml in a 1000 litre tank!
Until accurate and cheap ways to measure doc become available, if anyone is concerned about the levels just use granular activated carbon in addition to your scrubber. The carbon keeps levels of doc at reef levels as shown by advanced aquarist September 2008 so it is not removing ALL the food, just keeping it at natural levels. This works great with the scrubber which is extremely effective at keeping the inorganics at negligible levels.

[Marksfish]

Until accurate and cheap ways to measure doc become available, if anyone is concerned about the levels just use granular activated carbon in addition to your scrubber.

What sort of quantities of carbon are we looking at please? My green acro is very brown anf my purple plating monti is a copper colour. I'm sure it's not a light issue, so am looking towards carbon.

Mark

[chrisfraser05]

so a bag of carbon will do it?

[dtyharry]

It will certainly do no harm although as Santa said browning is usually caused by excess inorganic nutrients like nitrate and phosphate which carbon will not remove. All depends on whether you believe Santa who insists that you cannot have too much doc or whether you wish to maintain it at natural reef levels. Sps in particular have evolved in low nutrient, low doc waters.

[Marksfish]

But what size is a bag of carbon?

[chrisfraser05]

I'm very tempted to go back to skimming aswell as scrubbing but will decide after I boost the scrubber and let it settle a little.

[kerry]

I have never seen a use for carbon besides making my pocket book lighter or to remove meds in my FW tank decades ago. Have they come up with some new stuff???? Normally carbon only lasts a day or two max. What is in the carbon that traps or removes the DOC??? How does the carbon attach or grab DOC's and remove it from the water column??? SEE, ITS ALWAY THE DOC's THAT GET ME!!!

[Ace25]

This video better explains different carbons. http://www.youtube.com/watch?v=oVpRGzerJFI
And here is a good explanation on how it is made and how it works. http://www.wetwebmedia.com/ca/volume_7/ ... arbon.html (http://www.wetwebmedia.com/ca/volume_7/volume_7_1/carbon.html)

[SantaMonica]

but rather the coral absorbing the DOCs

Yes the coral animal itself eats DOC for growth. As your SaltAquarium quote says, it has nothing to do with zoox.


(The nutrients might increase the number of zooxanthellae in the coral, but it is possible that the nutrient overload increases the susceptibility of coral to diseases.)

Of course if ammonia is high, or even excess N and P, there would be a problem.


it is still a tiny fraction, think about it, one part organic carbon, 999999 parts water

Using your your own definition, 1ppm, it is the largest amount of carbon in the ocean (lakes too). If you don't think 1ppm is a lot, try 1ppm of phosphate, or 1ppm of ammonium. Why try to minimize the sound of it?


The carbon keeps levels of doc at reef levels

Bacteria and microbes keep levels of doc at (really, below) reef levels. Why are you adding vodka/pellets/zeo with one hand (in order to grow bacteria) and removing it with the other hand? DOC the the LIMITING factor in tanks. That means it is in SHORT SUPPLY compared to everything thing else needed to grow bacteria. That is why CARBON DOSING (ie. DOC dosing) works. Yes, dosing carbon is the same as dosing DOC, because vodka/pellets/zeo ARE doc. Don't you see how backwards you are making it sound?


Sps in particular have evolved in low nutrient, low doc waters.

What? Don't you remember anything of the studies that you said you read? The oceans, and especially reefs, have VERY HIGH doc levels.

[kotlec]

Very informative discusion by the way.

[Ace25]

Excess DOCs = more food for corals = more happy conditions for zoox to thrive and multiply... in extremes this leads to brown corals due to over saturation of zoox. What that point of "excess" is, is anyone's guess since we have no way to test for it at home, so we can only go on visual clues.. like my tank, first 5 months, corals went from brown to colorful because I took them out of another system with high DOCs into a new system with low DOCs. At month 5, corals started losing color again and browning out, at month 6, corals are now completely brown. I put in carbon last week and now the brown is very slowly going away and I am starting to see color in the coral again (colors other than brown). Pretty clear to me that excess DOCs is what is causing my issue with SPS corals. I do not have any browning problems with any other type of coral (LPS, softy, anemones.)

Not saying DOCs are bad, only excessive DOCs are bad in a closed system (aquarium). An ATS creates DOCs, not removes them. If you use an ATS only system for filtration, what method do you have in place to remove the DOCs from the system? If your relying on simply bacteria and corals to do that for you it is probably not going to be enough for almost all aquariums that have SPS corals in it. If you try to put in bio-pellets to eat the DOCs, you end up killing your ATS screen because the bio-pellets/bacteria will eat ALL the food out of the system much faster than the ATS can do it. The more the corals absorb DOCs, the more food the coral will create as a byproduct for zoox within the coral, making it a happy environment for zoox to multiply out of control in turn making SPS corals brown.

I love algae scrubbers, I think they are the best single type of filtration out there, but not without its shortcomings. DOCs being one of the shortcomings. Unfortunately for SPS keepers I do not see any way that an ATS can be used as the sole filtration method and no water changes. Either you need to add a secondary filtration type (carbon, skimmer, etc) or you need to keep up on weekly water changes in order to fill in the gap that the ATS has in terms of complete filtration. I am only talking about SPS coral tanks.. softy corals are much more forgiving and so are most LPS corals. As always, just my opinion.

[chrisfraser05]

From all my reading..... and I've been doing alot since friday lol... I would tend to agree with you there!

My sps seem fine if a little dull but its my Zoa's i've noticed browning mainly. going to look into this :)

[kerry]

I love this!! Well most of the time LOL. This means more research now!! I cannot get past the DOC's, AS ALWAYS!!! THIS IS MY BIGGEST HURDLE. There has to be something to control the DOC's. There has to be some kind of limiting factor to keep them as low as they are. If a tank cannot control DOS's then what is the problem??? It has to be flawed in some kind of way. The ocean can handle the DOC's with no problem. How does the ocean control them?? The ocean controls them by means of of ingestion (so to speak) by something that feeds on them and uses them up. If corals turn brown then I would assume that tank does not do a good job of mimicking what the ocean does. What limits a tank from performing like the ocean???? I believe there has to be some kind of factor there.

[dtyharry]

In new2scrub's post 'film algae on glass again', i mention a study by advanced aquarist in september 2008 measuring doc levels in various aquaria with different husbandry practices. Despite santa saying that the aquarium with high doc, over 5ppm, was a hastily constructed experiment that had not been given chance to mature, i do not believe this was the case. Check the acknowledgments, the water samples were supplied by a reef society with the exception of the author's own tank.

The tanks that utilised granular activated carbon all had levels of doc in line with healthy natural reefs, 1.1pmm +-0.4. Tanks with skimmers had higher levels than this if they did not use carbon as well, showing how ineffective skimmers really are. The only tank with elevated levels above 5ppm was the tank with no skimmer and no carbon filtration.


Bacteria and microbes keep levels of doc at (really, below) reef levels. Why are you adding vodka/pellets/zeo with one hand (in order to grow bacteria) and removing it with the other hand? DOC the the LIMITING factor in tanks. That means it is in SHORT SUPPLY compared to everything thing else needed to grow bacteria. That is why CARBON DOSING (ie. DOC dosing) works. Yes, dosing carbon is the same as dosing DOC, because vodka/pellets/zeo ARE doc. Don't you see how backwards you are making it sound?

There are many drawbacks to the carbon dosing route such as overdosing, bacterial blooms causing oxygen starvation and the lack of any scientific evidence as to how much and when etc. Also to run these systems it is essential to have a very oversized protein skimmer to remove the bacteria which is produced. You only need carbon dosing if your goal is to grow these extra bacteria which in a scrubber system is not necessary because the phosphate and nitrate are absorbed by the algae.

If you went the carbon dosing route without a skimmer the EXCESS organic carbon which you have dosed would increase bacterial levels to such a degree that you would probably kill all your fish and corals due to oxygen starvation. No, the bullet in your hand that is organic carbon did not kill you, but when it is fired through the gun that is increased microbial and bacterial growth, yes you will die. Good night!

[kotlec]

Harry,

Can we have guidelines to GAC usage? How much, how often, what type and so on ? I thing trying this wont hurt at all. My corals are brown, but grow like mad (except one kind of zoa) and my scrubber is 5 x too big as per new feeding guidelines.

[Marksfish]

A very interesting article (http://joejaworski.wordpress.com/2008/05/09/does-a-reef-tank-need-carbon/) on carbon and it's effect on DOCs.

Mark

[dtyharry]

February 2008 Advanced Aquarist did tests to see how long it took carbon to be saturated with DOCs and need changing. They took two different scenarios, one a skimmer set up with doc levels approximately 1ppm and an unskimmed tank at approx 7ppm. Taking a 100 gallon tank as an example it took approximately 40 days and 4 days for the low doc and high doc tanks carbon to become saturated respectively. That was using 100g of carbon.

If you think you have high doc then it might be worth changing the carbon maybe once a week to start and once everything has settled maybe once a month.
In the uk this would cost approximately £1 per month, very good value for peace of mind.

Fig 12 in that article shows a graph for different tank sizes and carbon amounts and the saturation times.

[Ace25]

I haven't mentioned this yet, but one BIG concern with using carbon is it is now scientifically proven to be one of the leading causes of HLLE, so if you have tangs and other fish susceptible to HLLE I would advise people NOT to use carbon in the system. I would use Purigen instead.

http://www.advancedaquarist.com/blog/ac ... le-disease (http://www.advancedaquarist.com/blog/activated-carbon-affirmed-as-causative-agent-for-hlle-disease)

http://www.advancedaquarist.com/blog/ac ... ne-erosion (http://www.advancedaquarist.com/blog/activated-carbon-indicted-in-inducing-head-and-lateral-line-erosion)

[dtyharry]

I haven't mentioned this yet, but one BIG concern with using carbon is it is now scientifically proven to be one of the leading causes of HLLE, so if you have tangs and other fish susceptible to HLLE I would advise people NOT to use carbon in the system. I would use Purigen instead.

Yes if that was a concern purigen seems like it would be a great alternative. Here in the uk a 1litre pack costs £50. 100ml treats a 100 gallon tank for up to one month at a time and can be recharged up to 10 times. Even if you only recharged it 5 times to be sure that is 50 months of treatment removing organics which is cheap i tink you would agree compared to a skimmer! Bet in the US it is cheaper as well.

Easy to tell when it needs recharging as it turns from white to brown/black. Anyone on here use it?

[chrisfraser05]

I'm interested!!!!!

So purigen does the job of carbon then???

[Doompie]

Very interesting discussion!

Here's my 2 cents:

I did some reading on DOC's and what they are, and what the effect is on corals. But there are only a few thing men can say about it..allot more is just unknown..

So here are a few of my findings..

Research on DOCS's on the Great barrier reef.. (http://books.google.nl/books?id=4hI5XCcYzUgC&pg=PA232&lpg=PA232&dq=dissolved+organic+carbon+great+barrier+reef&source=bl&ots=iptB7IzwD6&sig=BDL-y7oqewZuYnXivPo8-rvHwKg&hl=nl&ei=eCidTvrkL8mVOqS6rI4J&sa=X&oi=book_result&ct=result&resnum=3&ved=0CDsQ6AEwAg#v=onepage&q=dissolved%20organic%20carbon%20great%20barrier%2 0reef&f=false)

This research writes in short that an increased ammount of DOC leads to coral bleech followed by mortality...but it differes between species, so to generalise SPS is to rough..also the levels are way out of tank levels.

Standing stock of DOC is determined by a combination of carbon fixation via photosynthesis, consumption via heterotrophic bacterial growth, and import/export from exogenous sources.
In general the standing stock is 70-80 uM..

But they also state there is a huge differene between:
1) Labile DOC - is rapidly turned over within minutes to days, and represent a major dynamical component of the marine carbon cycle
2) Refractory DOC - can exist for thousands of years, maybe even milions and is Most of the measured standings..

DOC measurements on coral reeds however show significantly other number: 34 to 160 uM, suggesting there is variable production and use of DOC on each individual reef. DOC flux is higher above the corals reef structure than surrounding waters. DOC levels are highest above coral reefs, and get lower closer to the structure.

Measurements (eventhough where very hard) have pointed out that labile DOC is approximate 20% in some coral reef waters.

Other interesting facts according this research:
- Microbes consume most of the labile DOC and are carbon limited
- On coral reefs complex interactions between DOC, microbial growth and filter feeders exists

So the mortality problem is not the DOC is self, it is the uncontrolled microbial growth..(they outcompete the coralmicrobes)


Antoher research (http://www.mendeley.com/research/role-elevated-organic-carbon-levels-microbial-activity-coral-mortality-1/)

The abstract of that research:
"Here we experimentally show that routinely measured components of water quality (nitrate, phosphate, ammonia) do not cause substantial coral mortality. In contrast, dissolved organic carbon (DOC), which is rarely measured on reefs, does. Elevated DOC levels also accelerate the growth rate of microbes living in the corals' surface mucopolysaccharide layer by an order of magnitude, suggesting that mortality occurs due to a disruption of the balance between the coral and its associated microbiota"

Also there has been multiple researches on release of DOC from (SPS)corals, they do release DOC's. Most of it is labile but netto they don't though.

But one of the most interesting things i've read was this research (http://www.int-res.com/abstracts/meps/v409/p27-39/)

Abstract:
"Particulate organic carbon (POC) release was highest for corals (8.2 ± 4.2 mg m–2 h–1), followed by benthic algae (3.9 ± 0.7 mg m–2 h–1) and seagrasses (3.1 ± 2.0 mg m–2 h–1). Dissolved organic carbon (DOC) release rates were highest for seagrasses (15.8 ± 6.0 mg m–2 h–1), followed by algae (1.9 ± 2.0 mg m–2 h–1), whereas corals displayed net DOC uptake. Benthic algae-derived organic matter stimulated planktonic microbial O2 consumption significantly more than seagrass- or coral-derived organic matter. In situ O2 loggers revealed significantly lower average O2 concentrations, particularly during the night, at algae-dominated sites compared to other benthic lagoon environments. This indicates effects of algae-derived organic matter on in situ O2 availability. We therefore suggest that shifts in benthic primary producer dominance affect ecosystem functioning owing to differences in quantity, composition and microbial degradability of the released organic matter."


Also there is this reseach (http://moorea.berkeley.edu/research/projects/coupling-between-dissolved-organic-matter-algae-and-microbes-coral-reef-platforms)still ongoing untill 2012..
They try to find the Coupling between dissolved organic matter, algae, and microbes on coral reef platforms..

"The observation of low DOC measurements on degraded reefs is decoupled from the high abundance of macroalgae, which one might expect would raise levels of DOC through the release of photosynthate into the water column. To explain this apparent paradox we propose that reef degradation, and the associated phase-shifts from coral to algal dominance, leads to elevated levels of algal exudates in the water column, which allows the microbial community to utilize the standing stock of semi-labile DOC"


Research ends with:
"To futher understand the relationship between microbes, DOC,and coral reef decline there are many research questions to be answered.."

One conclusion we can make though: Fleshy algae release primarly/only Labile DOC..

I realy would like to suggest to everyone to have a look at this book:
http://books.google.nl/books?id=4hI5XCc ... al&f=false (http://books.google.nl/books?id=4hI5XCcYzUgC&pg=PA256&lpg=PA256&dq=dissolved+organic+carbon+macroalgae+coral&source=bl&ots=iptB7IDuAa&sig=N5It_RXV_iDFQCAAT1BvsYn-CI0&hl=nl&ei=NjedTpDNDsKgOpHY7dMJ&sa=X&oi=book_result&ct=result&resnum=5&ved=0CFAQ6AEwBA#v=onepage&q=dissolved%20organic%20carbon%20macroalgae%20cora l&f=false)

From page 241 it's all about the importance of algae..

*tip: search for the e-book version of "Coral Reefs: An Ecosystem in Transition"

Regarding the browning of the SPS:

There are so much more factors that come into play, here's an interesting article with a different perspective :
http://reefkeeping.com/issues/2007-01/atj/index.php


Final research which is worth reading: (2001)
http://www.rsmas.miami.edu/groups/bioge ... ansell.pdf (http://www.rsmas.miami.edu/groups/biogeochem/Hansell%20pdfs/33%20Hansell.pdf)

I think the conclusion says it all:
"We have more to learn about what limits the amount of DOC in the ocean, what controls its production and lifetime, and what DOC is composed of"

[Doompie]

So to draw a conclusion, I have to hook up with SantaMonica on this. Sorry for the Carbon guys but in my opinion that is a very bad idea..

When there is more O2 available, algae will consume DOC (also bacteria break it down with the help of O2). So inverse lighting regime for the ATS does not make sense.. (coral algae use O2 @night)
Also high flow ATS sounds like a very good idea..This will add significantly more O2 to your water column (vertical water can exchange much more).
In addition you want to have maximum oxygen exchange on surface, so open up the ATS, add a streamer to the sump (or airstone) and maximum flow in the display can help..(??)

Also found some interesting info regarding browning:

A guy names M2434 on 3reef did allot of research on this browning matter, here are is his conclusion:

"The zooxanthellae is located within compartments in the corals tissue and the coral can regulate access to certain nutrients to promote or restrict algae growth. Regardless though, the under certain environmental conditions, the algae is able to bypass the coral and use nutrients such as nitrate directly from the water. When this occurs the algae can grow faster and the corals perceived coloration becomes browner.

Also, here is some extra info

Although the exact mechanisms are largely unkown, we know that corals can regulate zooxanthellae growth, by regulating access to inorganic nutrients passing through the corals tissue to the zoox. For example there's evidence corals can divert CO2 to zooxanthellae in more productive areas of tissue, such as those areas that are better illuminated.

Also, there are cases where regulation doesn't happen, or happens too efficiently and zoox proliferates. However, I left out a few important parts, which Inwall75 mostly mentioned.

Zoox produces oxygen, but also along with this, some byproducts such as Reactive Oxygen Species (ROS) and also Reactive Nitrogen Species such as NO. These byproducts can damage the host tissue. So, the host and symbiont have mechanisms to remove this stuff and/or break it down, in order to maintain their relationship. There are cases though, where the alga proliferates so fast that the mechanisms become ineffective. However, as Inwall75 mentioned, in these cases, the host can often eliminate some of the algae through various means.

While it isn't exactly known, which stressors and at which levels cause these various outcomes, it can be inferred that more drastic outcomes are the result of more immediate threats to the host organism.

All in all, though, mainly through these various methods, it appears that in most cases, the coral can largely control the algae population density. If a coral is brown, due to lack of light for example, it seems that the coral is allowing the algae to proliferate, in order for the coral to receive the necessary nutrients to survive. So, in this case, the browning is sort of a good thing as it is helping the coral adapt to otherwise insufficient lighting.

Similarly, while light can reduce the zoox density, so can food. You could also argue that the coral requires more light because it isn't getting enough food. There seems to be some truth to this, as the availability of food is fairly low, in our systems compared to nature and average light levels over the course of the day are fairly high. (Actually, on a side note, this is somewhat of a fine balance, as there is a limit to how much light zoox can utilize and how much stress from zooxanthellae byproducts the coral can tolerate. This brings up another key component of SPS care; food!)

When browning does become a problem, it's when the zoox still can't keep up with the corals demands, or when the coral looses control over it's zoox. These also happen.

When a coral looses control however, it appears to be the result of synergistic effects of multiple stressors, not just a single stressor such as increase nitrate. For example, there are cases where a coral could turn brown when lighting is too high. I could hypothesize that this could occur if we have an old bulb, which has lost a lot of intensity, and in the meantime, nitrate levels have increased allowing the zoox density to increase. However, what we don't see is that the zoox density is being limited by lack of available light. However, now we replace the bulb and the algae takes off due to the increased intensity.

It happens fast enough, that the coral doesn’t limit it's growth through nutrient regulation fast enough, but if the stress isn't too much for the coral, it is not necessarily an issue and over time, the coral will regain it's coloration.

However, depending on the stress, it may need to expel some zoox, but if the stress is too great, it may even have trouble expelling the zoox fast enough. If the coral is able to restore balance, through these methods though, eventually, coloration will return. If not, some of the more extreme methods of zoox elimination may occur and the odds of survival decrease. If the stress is great enough however, it may just go strait to necrosis. There brings up another limitation of SPS corals BTW. Corals such as LPS corals can inflate and deflate to regulate their available surface area. So, in a situation such as this, they may buy some time by deflating and decreasing photosynthesis that way. An SPS coral can't do this."

[dtyharry]

When there is more O2 available, algae will consume DOC (also bacteria break it down with the help of O2). So inverse lighting regime for the ATS does not make sense.. (coral algae use O2 @night)
Also high flow ATS sounds like a very good idea..This will add significantly more O2 to your water column (vertical water can exchange much more).
In addition you want to have maximum oxygen exchange on surface, so open up the ATS, add a streamer to the sump (or airstone) and maximum flow in the display can help..(??)

Algae do not consume DOC, they produce it. They use carbon from dissolved carbon dioxide in the water, together with inorganic nutrients like phosphates and nitrates to grow.
Granular activated carbon or if you are concerned with that, something like purigen, will maintain dissolved organics at natural reef levels, without the aid of a skimmer.

[Doompie]

Algae do not consume DOC, they produce it. They use carbon from dissolved carbon dioxide in the water, together with inorganic nutrients like phosphates and nitrates to grow.
Granular activated carbon or if you are concerned with that, something like purigen, will maintain dissolved organics at natural reef levels, without the aid of a skimmer.

That's what I posted in my previous post (last post on page 3).. there are different types of DOC's. The types that algae produce are from the "labile" type (much smaller particals) and that is what bacteria feed on to break down the bigger particle DOC's, to turn them into smaller part, which again is food for the algae..

They do a better job when the O2 levels are at maximum. That's why I stated my "conclusion"..

this reseach: http://www.rsmas.miami.edu/groups/bioge ... ansell.pdf (http://www.rsmas.miami.edu/groups/biogeochem/Hansell%20pdfs/33%20Hansell.pdf)

See also this nice summary from SM from another research: viewtopic.php?f=2&t=1424 (http://www.algaescrubber.net/forums/viewtopic.php?f=2&t=1424)

[dtyharry]

That's what I posted in my previous post (last post on page 3).. there are different types of DOC's. The types that algae produce are from the "labile" type (much smaller particals) and that is what bacteria feed on to break down the bigger particle DOC's, to turn them into smaller part, which again is food for the algae..

I do not get what you are saying, do you mean algae consume DOC? If so that is not the case, they need three main nutrients, carbon, nitrogen and phosphorous. Algae are primary producers and obtain their carbon from inorganic sources ie dissolved atmospheric carbon dioxide, not DOC. It does not matter how big or small. Eventually the vast majority of DOC is progressively reduced further and further by microbes, bacteria etc and are eventually oxidised to carbon dioxide.

Where is santa when you need him?

[Doompie]

think were on the same page, all I'm saying is that algae feed "good" DOCs to decomposers to break down the "bad" DOCs to n,p and co2..

This process is most efficient when the O2, for both the algae and the decomposers, is at maximum levels.

So algae stimulate the breakdown of "bad" DOCs..and that process ends up with food for the algae..

[chrisfraser05]

Bang!!!!!


That was the sound of my head popping lol

[Doompie]

The carbon is being used in the process called respiration..

Respiration takes carbohydrates and oxygen and combines them to produce carbon dioxide, water, and energy. Photosynthesis takes carbon dioxide and water and produces carbohydrates and oxygen.

[kotlec]

!! bang !!!

theres another one

[Ace25]

Great informative posts here! Love these types of threads. Thanks for your contributions to the discussion Doompie.


Anyone on here use it?

So purigen does the job of carbon then???
Yes, I used Purigen from 2000-2009 on my tanks. I works just like carbon but can be easily regenerated and reused. I stopped using it when I started using Rox 0.8 carbon because I felt the Rox carbon was able to get more out of the system than Purigen, ie. Rox carbon has a greater range of pore sizes in order to catch a larger variety of stuff. Nothing scientific, just observation behind my thoughts. Although Rox is getting to be a drain on the wallet having to buy it all the time, so after I run out I will be switching back to Purigen.

[chrisfraser05]

could you tell us about the rest of your filteration system ace?

Do you skim too?

[Ace25]

could you tell us about the rest of your filteration system ace?

Do you skim too?
Pretty simple. I have 2 reef tanks running. Both have all types of corals from softies to SPS.

Tank 1, 75G (30"x24"x24"). Filtration = ATS w/ LEDs fed via overflow and Bubble Magus NAC7 skimmer and about 40lbs of live rock in the display. Vortech MP40 + 1100GPH closed loop for flow.
Tank 2, 55G (48"x15"x18"). Filtration = ATS w/ 42w CFLs fed via dedicated pump and mesh bag of ROX 0.8 carbon in the overflow box and about 50lbs of live rock. 2 Koralia 1400's for flow.

[chrisfraser05]

so you seeing similar results in both tanks?

[Ace25]

No, the 75G tank not running carbon has a much higher DOC level, so high SPS corals brown out in it within days, even though the skimmer is rated for 2x the tank size. Skimmer is doing nothing (good) in my opinion on that tank. Waste of $300. Although that is the tank that has great ATS growth. On the 55G tank I could go 3 weeks and not get 1/2 the growth that I get in under a week on the 75G tank. I need to switch over to LEDs on my 55G tank. I never got great growth with CFL bulbs, ever... but never knew that until I switched one over to LEDs and saw the difference. I do not think CFLs are very good at all for an ATS, I do think T5HOs like on the SM100 scrubber is much better than CFLs, but I think LEDs are by far the best from my experience.

[Aeros]

This topic is relevent to two of my recent post questions. Green water, and brown SPS.

I did run carbon as i knew it would reduce the tint in the water. As a bonus i got blue corals again. Did not connect the two.

So i stopped carbon... 3weeks later im back to brown. Water was like lemonade too. 20k radiums and my tank looked like a fresh water set-up hah!

Glad i checked this forum when i did. Got my carbon reactor on double duty. Seeing blue again. Corals and lights!

[chrisfraser05]

woop woop.......


I've got a feeling this is my best posed question/thread since I've been in the fish game lol

[marineguy]

New scrubber guild lines use carbon? :?

[Ace25]

New scrubber guild lines use carbon? :?
Naw.. I wouldn't say that. There are far to many people with tangs in their tanks to add "use of carbon" to the guidelines. Carbon works great in certain scenarios, but purigen would work better in others, and as SM's tank shows, no use of anything could work fine also. It comes down to the individual tank and what type of DOC removal tool you want to use on your system.

[Floyd R Turbo]

BANG!!

SM, I think we need an FAQ article regarding DOCs DOMs etc and what algae consumes and forms, what is releases and doesn't release, etc. I read the first half of this thread and then glossed over the rest. I think it is a subject that the purists use to poo-poo the scrubber. It needs much clarification for me...

[kotlec]

Exactly my thoughts . Thumb up.

[kerry]

BANG!!

SM, I think we need an FAQ article regarding DOCs DOMs etc and what algae consumes and forms, what is releases and doesn't release, etc. I read the first half of this thread and then glossed over the rest. I think it is a subject that the purists use to poo-poo the scrubber. It needs much clarification for me...
I think thats a great idea! An area with dosing info would also help a lot of us here to.

[Doompie]

I think this says it all / explaint allot:

http://www.reefkeeping.com/issues/2003- ... /index.php (http://www.reefkeeping.com/issues/2003-01/rs/feature/index.php)

Conclusion quote:
"Export of excess materials is facilitated by the use of harvestable algae, and together with reasonable filtration by foam fractionation or other means will help keep the system stable and healthy with a minimum of maintenance. Scientists and researchers call these small ecosystem analogues "microcosms," and they have been used in marine research since the 1960s. They are a tried and tested type of system that promotes animal health. A lot of researchers use them for two major reasons: they keep the animals healthy, and they require a minimum of effort and maintenance."

[SantaMonica]

Excess DOCs = more food for corals = more happy conditions for zoox to thrive and multiply

It's actually the coral host, per se, that used the DOC; not the zoox (zoox mostly eat inorganics).


in extremes this leads to brown corals due to over saturation of zoox.

It's the higher levels of inorganics, not organics, that cause "over saturation" of zoox.


corals went from brown to colorful because I took them out of another system with high DOCs into a new system with low DOCs.

They went from high N and P, to low N and P.


If you use an ATS only system for filtration, what method do you have in place to remove the DOCs from the system?

Bacteria. The same thing that eats the DOC's added by reefers when they add vitamins, amino's etc.


If your relying on simply bacteria and corals to do that for you it is probably not going to be enough for almost all aquariums that have SPS corals in it.

Yes it is. The bacteria multiply indefinitely, with no limits, until they run out of food. If they multiply enough, you see them, like in over-dosed vodka tanks (slime). In scrubber-only tanks, they never grow that much.


If you try to put in bio-pellets to eat the DOCs

Bio pellets do not eat DOC.


you end up killing your ATS screen because the bio-pellets/bacteria will eat ALL the food out of the system much faster than the ATS can do it.

The pellets eat the inorganics (N and P), not the DOC (organics).


The more the corals absorb DOCs, the more food the coral will create as a byproduct for zoox within the coral, making it a happy environment for zoox to multiply out of control in turn making SPS corals brown.

But the corals modulate the living conditions of the zoox. What the coral can't modulate, is the N and P from the surrounding water.


for SPS keepers I do not see any way that an ATS can be used as the sole filtration method and no water changes.

Ask those who do.


There has to be something to control the DOC's

Bacteria. Google "doc microbial loop". It's what controls all the food in the oceans and lakes.


There has to be some kind of limiting factor to keep them as low as they are

Bacteria/microbes.


If a tank cannot control DOS's then what is the problem?

If you mean the problem of brown sps, then I am working on a hypothesis. Problem is, everyone has brown sps, no matter what filters they run.


How does the ocean control them?

Bacteria/microbes.


If corals turn brown then I would assume that tank does not do a good job of mimicking what the ocean does.

Correct. "Distributed filtration" is one theory; Insufficient coral lighting, is another.


What limits a tank from performing like the ocean?

Distributed filtration, or lack of.


Also to run these [carbon dosing] systems it is essential to have a very oversized protein skimmer to remove the bacteria which is produced.

As a side note, I've run skimmer-less carbon dosing before. It does work.


DOC flux is higher above the corals reef structure than surrounding waters. DOC levels are highest above coral reefs, and get lower closer to the structure.

This is the "rate" that I was trying to explain before. You can have a rate of organics, and a rate of inorganics. A higher "flux" (rate) usually means a lower standing stock (level).


Microbes consume most of the labile DOC and are carbon limited

Yes, and "carbon limited" means DOC limited. Meaning, the microbes have consumed "almost all" the DOC available.


There are so much more factors that come into play, here's an interesting article with a different perspective :
http://reefkeeping.com/issues/2007-01/atj/index.php

"Corals can control (or at least limit) the populations of zooxanthellae in their tissues by controlling the amount of waste they release to the algae."... this is what I was referring to, above.


When there is more O2 available, algae will consume DOC

No, the algae consume inorganics (N and P), not DOC. Also, the O2 does not really play a part in how much the algae consume.


So inverse lighting regime for the ATS does not make sense.. (coral algae use O2 @night)

They use a very small percentage of O2, compared to what they give off in the light.


high flow ATS sounds like a very good idea..This will add significantly more O2 to your water column (vertical water can exchange much more).

Not sure it will add more O2, but the idea is to approach a "distributed filter" state. The slower the flow is, the less "distributed" the filter is, and the more "discrete" it becomes. Still a theory though.


If a coral is brown, due to lack of light for example, it seems that the coral is allowing the algae to proliferate, in order for the coral to receive the necessary nutrients to survive.

Yes good point; a brown color is actually mostly a healthy condition, which generates more food for the coral in lower-light conditions (thus, more zoox surface is necessary to generate the same amount of food). So more coral lighting would give reason for the zoox to reduce.


Similarly, while light can reduce the zoox density, so can food. You could also argue that the coral requires more light because it isn't getting enough food.

Another good point; studies have shown that coral deaths on reefs can be reduced when there are more food particles in the water. And lord knows that nobody's tank has even 10 percent of the food particles in the ocean. I recently got up to 50 percent (feeding an equivalent 72 cubes a day), but my two scrubbers could not handle it.


When browning does become a problem, it's when the zoox still can't keep up with the corals demands

I like this viewpoint. The zoox is trying to compensate for lack of something, and it looks like lighting may be it.


Granular activated carbon or if you are concerned with that, something like purigen, will maintain dissolved organics at natural reef levels

GAC or Purigen or whatever, has no idea what natural reef levels are. It will just absorb until it is saturated.


there are different types of DOC's. The types that algae produce are from the "labile" type (much smaller particals) and that is what bacteria feed on to break down the bigger particle DOC's, to turn them into smaller part, which again is food for the algae..

I think what you mean is, the DOC is broken down into inorganics (N and P) by the bacteria.


They [bacteria] do a better job when the O2 levels are at maximum.

True, but in scrubbed tanks, O2 is usually always high, especially if in reverse photoperiod.


I think we need an FAQ article regarding DOCs

Probably a bit soon for that... I want to see how some theories work out first.

1st theory: The more distributed a filter is, the better it may approach reef conditions.
2nd theory: Scrubber tanks *may* be able to use much higher display lighting levels, and thus provide much higher growth levels.

[Aeros]

It's purely anecdotal on my part. But I had brown corals, and green water. Most of my SPS grew so fast that they encrusted the frag racks two or three squares away in a matter of a month. But, they were brown except my montipora and milipora and LPS/Softies.

I ran carbon in a BRS reactor and saw them go from brown to green within a day plus. Pulled the carbon after 36hrs and within two weeks my SPS were browning again.

I have since ran GAC almost continuously, and am getting green back to blue SPS. I cannot say anything about growth yet. But the water/rocks/coraline/sps color/ all look better. As always N/P are zero. Cal/Carbonate are rock solid 420/10 due to cal reactor.

What excess in the water column that GAC removed is responsible for this? Aside from GAC or similar do we have a treatment?

[kotlec]

Do I understand correctly?



It's actually the coral host, per se, that used the DOC; not the zoox (zoox mostly eat inorganics).


Zoox eat N+P and make DOC to feed coral.
Coral can eat DOC with no help of zoox if present. Or it can only eat DOC fed from zoox as it has no mouth to eat it from water column ?
Bacteria eat DOC and make food N+P for algae and zoox .
Algae eat N+P and make DOC again.

[Ace25]

corals went from brown to colorful because I took them out of another system with high DOCs into a new system with low DOCs.

They went from high N and P, to low N and P.

You know what they say about "assumptions", right? ;) Here are my tests from this morning. The 55G tank is the one the SPS corals are doing good in. The 75G is the one that has super growth on the ATS and right now only about 20lbs of live rock in the system. I took out most of the rock due to an aiptasia infestation so I am nuking/cooking the rock right now. I removed the rock AFTER the SPS corals died off, so the minimal rock/bacteria surface wasn't changed until after the corals died.

75G tank, ATS/Skimmer
http://farm7.static.flickr.com/6111/6295415900_b1b094c22d_z.jpg

55G tank, ATS/Carbon
http://farm7.static.flickr.com/6111/6294887507_7dff63b45c_z.jpg

Here is what my 75G tank use to look like when I ran Rox 0.8 carbon in it, since I stopped using carbon DOCs are out of control in the tank.
http://farm3.static.flickr.com/2559/3914071006_fb0b8b9e9a_z.jpg?zz=1

Now the tank is a wasteland. 95% of the SPS corals died and the 5% that were left I moved over to my other tank, and they have come back AND colored up. When my lights come on I will take some pictures of some acros that were completely browned out and since moving to a system with carbon, have now got quite a bit of blue in the top 1/2 of the coral and the blue is moving downwards replacing the brown more and more each day, even though BOTH systems are identical in terms of N/P, only difference is one uses Carbon for DOC removal, the other uses a Skimmer (which we all know doesn't remove DOCs well at all).


[quote][quote:2ac0fl8t] If you use an ATS only system for filtration, what method do you have in place to remove the DOCs from the system?

Bacteria. The same thing that eats the DOC's added by reefers when they add vitamins, amino's etc.


If your relying on simply bacteria and corals to do that for you it is probably not going to be enough for almost all aquariums that have SPS corals in it.

Yes it is. The bacteria multiply indefinitely, with no limits, until they run out of food. If they multiply enough, you see them, like in over-dosed vodka tanks (slime). In scrubber-only tanks, they never grow that much.

But the corals modulate the living conditions of the zoox. What the coral can't modulate, is the N and P from the surrounding water.


for SPS keepers I do not see any way that an ATS can be used as the sole filtration method and no water changes.

Ask those who do.[/quote:2ac0fl8t][/quote:2ac0fl8t]

I disagree with you on the "bacteria" part. In the ocean, sure, I can see it working, there are millions of variations of bacteria all doing different jobs to keep the ocean clean.. in an aquarium, there is no possible way to get that type of bacterial diversity because we do not have the ability to do so (ie. cold water/deep water bacteria in the same system like the ocean has). Unless you employ a means to boost bacteria levels to compensate for DOCs (ie. carbon dosing) I still feel there is no way for bacteria to solve the problem in a closed system.

Even with carbon dosing, your only multiplying the strains of bacteria in your tank, your not adding any diversity. There are good and bad types of bacteria, when one carbon doses, how do they know what levels of good vs bad bacteria are in their tank already, and how do they know that by carbon dosing they won't end up feeding the the bad type of bacteria because that is the majority of the bacteria in their system (ie. Cyanobacteria), causing more problems than resolving? I still feel carbon dosing is "voodoo" and goes against the golden rule of reefkeeping, which is to never add anything to your system that you can not test for. I understand how carbon dosing works, and understand it does work in certain scenarios, BUT, it is still just a guessing game of "how much carbon dosing should I do, and how do I know when I have enough bacteria to do the job and NOT too much that it would harm the ATS growth". No one at home can answer that question, so since you can't answer the question because there is no way to test for it, why do it at all? Seems like a HUGE risk and you end up making a tank on the verge of crashing any second due to the unknown parameters in the tank (bacterial levels).

And for the last part of your quote, can you please point me to someone who has an entire tank filled with SPS corals like my picture above that I can "ask those who do" like you suggest? I don't know anyone that has a full tank of SPS corals and ONLY run an ATS, every one I have seen has some type of secondary filtration method to control DOCs.

[Doompie]

How much light do you have above your tanks ace25?

As I understand Santa Monicas post, it's all a balance between docs, light and nutrients..controlled by algae, bacteria and the corals self..

[Ace25]

I have DIY LEDs above both my tanks. 48 LEDs above the 75G and 24 LEDs above the 55G. I have a PAR meter and place corals in PAR areas suitable for the coral.

I understand the process as well... and it works well.. in the ocean. I just don't think it is possible to recreate all of it in a box of water. We can use the parts suitable for our needs, like using algae to clean the water, whether it be a refugium or an algae scrubber, but other aspects we simply can not replicate 100%, bacteria diversity being one. It has been tried many times, adding "zones" to a system in order to grow a larger variety of bacteria, things like coil denitrators, plenums, deep sand beds, carbon dosing (liquid=system wide / bio-pellets=zone), but as far as I know none of them work 100%. Some will help only slightly, like large coil denitrators, but take up too much room for the small benefit the provide, others usually only work short term, like plenums and DSBs, but eventually they both seem to go bad after a few years use and can end up being a much bigger risk to the tank when they go bad.

Carbon dosing is just providing more food for the bacteria in the tank to eat and multiply, which types of bacteria multiply is anyones guess. It has shown to work great for a lot of people, and has been shown to cause major problems for almost as many. Even when it is working great to me it is like balancing a stack up glasses on a tray constantly, one slip up and it all comes crashing down. Too much food and you get slime blooms, if you have a good start but months down the road you slack off and stop dosing, or bio-pellets run out, the bacteria could have a mass die off and cause issues.

If others want to experiment with carbon dosing I say go for it... I have tried vodka and pellets myself, failures both times, but I had to experiment myself to learn and be able to have an opinion. I know all tanks are different and every result will differ in some way so I am not against anyone trying any method on their own tanks to see what works best. This goes back to my tanks, and why I feel DOCs is the issue with my SPS corals. I know what filtration methods I am using, lighting, PAR readings for corals, using same salt and ro/di water, so I can draw some type of conclusion of what differs between the 2 tanks, and really, it does come down to one tank using carbon and the other isn't. When I can take a coral out of one tank that is completely brown and under 400 PAR, and place it in the other tank with the same Cree LEDs and the same PAR reading, and it starts to color back up within a week, even though both tanks have identical N/P readings, to me it really does point to one thing, DOCs.

As promised. Pics. 2 SPS corals, same coral, one taken out a month ago and placed in the tank with carbon, one taken out a week ago. Coloring up nicely.

Acro - 1 week in tank with carbon
http://farm7.static.flickr.com/6222/6296382168_46942ca896_z.jpg

Acro - 4 weeks in tank with carbon
http://farm7.static.flickr.com/6039/6296382148_ceaab3ed4c_z.jpg

[kotlec]

Hypotetically - Is there anything else, that can be removed by carbon and have something to do with your acro color ?

I have same acro. It has only tips blue. The rest brown. I run carbon in the bag. Green acro is green and birdsnest is pink BTW.

[Ace25]

Hypotetically - Is there anything else, that can be removed by carbon and have something to do with your acro color ?

I have same acro. It has only tips blue. The rest brown. I run carbon in the bag. Green acro is green and birdsnest is pink BTW.

Hypothetically... sure, it is entirely possible the carbon is removing something other than DOCs and is the reason my SPS corals do horrible. I am completely open to any suggestions to what that may be. If someone can point me to something else other than DOCs being the cause to my brown SPS corals that is logical I will be the first to say it sounds like a more reasonable cause to the problem. Carbon removes heavy metal contaminants and toxins to name a few other things besides DOCs. One possibility is my closed loop pump may have good bad/rusted inside. I have not checked it since I installed it 4 years ago (although I just ordered a ReefFlo Blowhole 1450 pump today to replace it). It still runs and pushes water, albeit 50x louder now than when I originally installed it. When I used to run carbon on that tank, SPS corals did fine, since removing the carbon, not so... BUT something like a faulty pump could also lead to issues like I am seeing through heavy metal poisoning. I have used the same sand and rocks in both tanks, so we can eliminate something like copper leaching from rocks, both tanks are grounded, so stray voltage isn't an issue, but a faulty pump will cause issues. It could even be my skimmer pump. The Atman2500 used on the Bubble Magus skimmers are cheap china pumps, and I have already had 1 fail, maybe the second one is going bad?

So next week I will replace my close loop pump, remove my skimmer completely (I really don't think it is helping), and clean my Eheim1262 return pump to make sure all pumps are working properly. Heaters are both new and working properly, I replace 2 200w Jager heaters yearly on my 75G tank as part of my normal maintenance. If I see anything bad with the pumps, which I hope not to, I will take pictures and show everyone and admit that was more likely the cause of my corals demise.

As for green acro's, well, from what I have been seeing, some SPS corals go from brown to green first.. then other colors come in. I have a Crayola acro that browned out, then turned completely army green, and now is getting purple tips and other colors within it. The coral in the above picture, some wild acro I have no ID for, in the past and in other peoples tanks normally has white bases on the lower 1/2 of the branches and purple on the top 1/2, brown coralites, and the encrusting brown base usually has a green tint to it.

[kotlec]

Any sugestions why my acros still brown ?

[Ace25]

Any sugestions why my acros still brown ?
How much carbon are you running? What type of carbon? And how often are you replacing it? On my 55G tank, the one that corals are going better in, things were good the first 5 months after setup, then at month 6 was when I think DOC levels got too high and some SPS corals browned out (They were brown in the 75G tank, moved them over to the 55G and they colored up for months, then started browning again in that tank). That was when I added carbon. I put in A LOT of carbon to reduce the DOCs initially. 3 cups of ROX 0.8 carbon replaced weekly for the first 3 weeks was what I did, 2 cups worth in a filter bag in the sump and 1 cup in a filter bag in the overflow... now I am using 2 cups of carbon in a bag in the overflow and replacing it every 2-3 weeks since my corals look like they are moving in a positive direction. Just going off observation, but I think the DOC levels are good now and why the corals are coloring up more each day. Similar thinking with carbon as people who are working on a Phosphate problem. If you have phosphates in the 1.0+ range and try and use GFO to fix the problem, it is going to take a ton of GFO initially to do that much work, a reactor full and replaced every 2 days for a month to get levels down to the .03-.09 area, but once you get levels down you can use a smaller amount and replace it far less frequently. Only difference is I can't measure DOCs like I can phosphates, I can pretty much only go off observations to give me clues on how things are going and guess on the correct amount of carbon and replacement schedule.

[kotlec]

Im using best carbon I could find. I will try to use more to make initial clearance. That's good idea.

BTW how many is cup ? Is it kind of american standard ?

[Aeros]

Im using best carbon I could find. I will try to use more to make initial clearance. That's good idea.

BTW how many is cup ? Is it kind of american standard ?

Invented by Stanley, It's a unit of measurement based off of a semi-annual award given to a group of players who hockey the hardest against other hockers.

[kotlec]

Then I have much to do. First buy skates, then learn to play hockey. Lastly I have to win cup. Only then I will be able to measure right amount of carbon for my tank :mrgreen:


Seriously google helped me : A metric approximation to the US cup measurement equal to a quarter of a liter.

[Doompie]

Finally found some research that kinda points this issue out:

From the book "Coral reefs an Ecosystem in transition" Part III "Light as a Source of Information and Energy in Zooxanthellate Corals" - chapter 8 - Energy and Nutrient Fluxes..

So Browning is an swing of Zooxanthellae, right?

Quotes from research:

1) "with the assumption that within a colony under normal conditions, the symbionts are maintained at their carrying capacity, and their multiplication is further controlled by shortage of nutrients needed to match the carbon influx and the translocation of most carbon skeletons to the animal host. That the true doubling potential of the Zooxanthellae is on the order of a few days to a week has been demonstrated when corals are provided with seawater replete with nitrogen and phosphorus (Falkowski et al. 1993) and in the fast repopulation of experimentally bleached colonies (Koren et al. 2008)."

2) "The nutrient-limited, high-light corals readily respond to host factor stimulation and excreted as much as 250% against seawater as 100%. Interestingly, no such response is seen in low-light corals (Fig. 16). We interpret these resullts to be due to the relatively useless carbon acquired under high light that under nitrogen and phosphorus limitation cannot be utilized by the zooxanthellae for cell doubling. In the shade, each carbon atom can be used with the corresponding nitrogen and phosphorus ratios for new cell building (Dubinsky and Berman-Frank 2001)."

Zooxanthellae have the ability to decrease the amount of carbon taken by photosythesis, simply by lowering the photosythesis capacity..and that is darkening themselfs..

So the conclusion is that OR you have too much light for that coral so it can aquire too much useless carbon, combined with too low nutrients, which stimulates the browning of the Zooxanthellae..Or too much nutrients vs. too less light...

Another conclusion that can be made regarding this research:
When you have a "booming" growth of zooxanthellae (which makes them also looks brownish) it's only a case of too much nutrients (N and P).

Some good light info...: http://www.fishchannel.com/saltwater-aq ... light.aspx (http://www.fishchannel.com/saltwater-aquariums/aquarium-frontiers/natural-reef-light.aspx)

For those who are interested, some info regarding DOC's and bleeching here:
http://sites.google.com/site/coralreefs ... umentaries (http://sites.google.com/site/coralreefsystems/videos/mini-documentaries)

[Ace25]

Fantastic post Doompie!


Another conclusion that can be made regarding this research:
When you have a "booming" growth of zooxanthellae (which makes them also looks brownish) it's only a case of too much nutrients (N and P).
I still think there is more to this statement. Sure, the end result is true, but what actually leads to "too much N/P"? I still think corals absorbing excess DOCs and secreting N/P in the process is also a major factor to browning. You can't get much closer to the source for food (N/P) than zoox living inside a coral that is secreting food to feed the zoox. Kind of like how Santa Monica explains nutrient buildup in tanks, the rocks get it before the scrubber and feed algae in the display, in this case the corals feed the zoox before the scrubber can remove it. Just how I am thinking today.. more research may make me change my mind though. I certainly don't want anyone thinking I have the answer to this question, I just have theories. ;)

[Ace25]

I saw Santa Monica posting on other sites about "too little light" being a cause of browning when coupled with too much food in the water. I want to show this is not the case for me. I actually replicate the SUN at mid day with my LED light (~2000 PAR!). So SUPER high light (much higher than typical MH setups ever got, not even a 1000w MH will touch my LED light in PAR output) and high nutrients still = dead corals. Not bleaching dead, but browning out, no polyp extension, and slow death over the course of weeks/month, not a RTN type event.

http://www.youtube.com/watch?v=bElFSUmg5MY

I no longer use any T5s, this pic was taken the first day the LED light replaced my 400w MH (which got 850 PAR with a 10k bulb).
http://farm6.static.flickr.com/5204/5308115753_64db730737.jpg

http://farm6.static.flickr.com/5046/5301367855_d3678199b7.jpg

[Floyd R Turbo]

I can't say that I speak from direct experience here, but I do recall reading in multiple places that when the switch-over from MH to LED happens, people tend to tune their light output to mimic what they were getting from the MH lamps, and the light is actually much more intense and focused than it was before. IIRC this led to some coral death and bleaching events. One thing I have also read many times is that PAR meters are not very good at registering blue light correctly. The bottom line here is that I think it would be good to look at some information on these types of things as well.

I know from my conversations with hydroponics guy when designing my LED scrubber fixture, he did not have very much good to say about PAR meters in general, mainly that they are not very reliable or accurate unless you get a very expensive one that can pinpoint a specific spectrum rather than giving you overall PAR, because that really doesn't tell you that much apparently. Also the same guy was closely involved in the development and design of a reef LED fixture, and his comment was that royal blue trumps all for growth, everything else is pretty much just for aesthetics. I can't quite tell from your pic of your fixture, but it looks like you have some 425/435 blues (the purple ones) and some cool whites. These may not be contributing as much to coral growth as the RBs are and may factor into this issue.

But again, this is all just regurgitated information. I could be completely off base, so feel free to correct anything I may have misinterpreted.

[Ace25]

I hear you 100% on the "switching to LEDs" thing. I actually agree 100% with it as well. A person has to understand how light works, what spectrum does what, and how much of what spectrum your using. I have a very good understanding of how light/spectrum/PAR works. Once you understand all that, you can still make use of a PAR meter. I agree, they are certainly not the most accurate tool, but even at $500 it is still the cheapest "light tool" and still useful if you understand how to use it and understand the spectrum your testing. Luckily I have a spectrometer at my disposal at work and have tested many light bulbs and LEDs myself to get spectral graphs and know what I am putting over my tank.

The reason why you can't just switch MH to LED and keep the same intensity is quite simple, MH lights put out a lot of spectrum that falls outside of the photosynthetic peaks. So most of the bright light we see is for our eyes and to see the different colors in the tank, where as with LEDs, the standard 50/50 mix of Royal Blue and Cool white puts out A LOT more 455nm light than any MH ever could. It is also a dim looking spectrum to our eyes, so we put a ton of blue to balance out the whites. If it were cool blue instead of royal blue it probably wouldn't be as big of a problem since most of those fall outside the photosynthetic peaks, but they also do not make corals glow like royal blues and actually make the water look like Windex to some if you use too many. So it is a double edge sword, we love the look royal blues give out, but by adding so much we harm our corals. To top it off, Cool White leds also put out a lot of 455nm blue. So when you add a light that is a 50/50 mix and turn it up to the intensity that the MH appeared to be, we are actually throwing 2x the amount of light at it in the 455nm range, which is why corals react negatively very quickly when you do this, usually by bleaching or RTNing.

So, knowing that a MH spectrum and the LED spectrum are quite different you can adjust your PAR ranges accordingly. It takes some re-learning but it is still easily done. It took me a year of checking PAR levels at certain corals under MH lights to get a feel for PAR levels for different corals, and with LEDs, even trying to calculate and adjust accordingly, it still took some re-learning to figure out what the new PAR reading corals liked. My light can do 2000 PAR at the surface, I don't run it that high (yet). I started off erroring on the low side so when my SPS corals were at 500 PAR before, I set them at 200 PAR under LEDs. I have since been slowly raising the PAR levels over the course of a year (next week will be 1 year running LEDs for me) and I am now actually up to 600 PAR at the coral and still brown.

On my first fixture (the one pictured above) I added different LEDs to cover the entire spectrum, ie. 12x royal blue, 8x cool blue, 4x cyan, and 16x cool, 4x neutral, and 4x warm whites. I wanted to cover the entire spectrum and since 420nm LEDs were not out last year, I ran 420nm T5s with the LEDs to cover the low end of the spectrum. One of the things I have said since the day I started using LEDs for projects is we really need full spectrum colors, like a full spectrum blue that is 420nm-480nm. This way we get the blue look we like without throwing an insane amount of a specific spectrum like royal blues. On my other light I run a simple 50/50 mix after seeing all those extra LEDs in my first fixture really didn't add much other than control over the color of the tank, but I also planned for that by having 48 LEDs over a 30"x24" footprint where as my other tank I have 24 LEDs over a 48"x14" footprint. Less LEDs, bigger area to cover, but since it is royal blue and cool whites, I don't need much to make my corals happy with the light they are receiving. That is the tank my corals are coloring back up in by using carbon in the tank. The last brown SPS stick I took out was under 600 PAR, and brown as can be, within a week under 400 PAR it started to color up. To me 600 PAR in one tank is = to 400 PAR in the other because the PAR I am getting @ 600 includes a lot more spectrum that fall outside the photosynthetic peaks and are almost useless to the corals. So same light levels in my opinion, higher light levels than my MH light before, the only difference is I use a lot of carbon in one tank and that happens to be the tank the corals regain color in.

Santa Monica has a nice theory, and I am not going to say he is wrong, I certainly do not have enough data to say anything close, but I do have my personal experience and it is telling me I don't think adding more light to a SPS tank run with only a scrubber will solve the issue we are talking about in this thread. As easy as it is to say "throw more light at it", there is a very complex method to actually doing that.

[dtyharry]

The only thing you have to worry about with elevated levels of doc are massively increased microbial growth on the coral surface which literally starves the coral of oxygen. Of this there is now no doubt. The debate as to whether aquariums with scrubbers produce excess doc will not end until accurate measurements are taken, currently beyond the scope of hobbyists.
It is no more complicated than that.
If you want to ensure your doc levels remain at natural healthy reef levels use activated carbon and if you are worried about tangs and lateral line disease and such use purigen or similar to keep levels low.
We can all argue until we are blue in the face but if you think your scrubber is producing excess doc which has not been proven incidentally, either stop using a scrubber or use carbon etc.

[Ace25]

if you think your scrubber is producing excess doc which has not been proven incidentally, either stop using a scrubber or use carbon etc.
1982 just called, they want you to read their studies on the topic. ;) There really is no question on "if algae produces DOCs", the question is how much DOCs does your scrubber produce (each one will be different), how harmful are excessive DOCs in a closed system to different types of corals, and what is the best way to keep DOC levels at natural reef levels safely and consistently, preferably a natural method vs using a media that needs frequent replacing.

http://www.jstor.org/pss/2836178

http://www.int-res.com/articles/meps/116/m116p309.pdf

http://www.mendeley.com/research/charac ... ic-carbon/ (http://www.mendeley.com/research/characteristics-reactivity-algaeproduced-dissolved-organic-carbon/)

[Marksfish]

I kinda understood this thread when it started. It has begun to get all sciency now and has confuddled me :?

I put carbon in my system when this thread started and parts of my acro have started to look green (first time ever), my purple plating monti is not the dull brown it was, but is still brown. I may put a polyfilter in and see if it changes to the DOC colour (brown I think, how apt!!).

Mark

[dtyharry]

if you think your scrubber is producing excess doc which has not been proven incidentally, either stop using a scrubber or use carbon etc.
1982 just called, they want you to read their studies on the topic. ;) There really is no question on "if algae produces DOCs", the question is how much DOCs does your scrubber produce (each one will be different), how harmful are excessive DOCs in a closed system to different types of corals, and what is the best way to keep DOC levels at natural reef levels safely and consistently, preferably a natural method vs using a media that needs frequent replacing.

http://www.jstor.org/pss/2836178 (tel:2836178)

http://www.int-res.com/articles/meps/116/m116p309.pdf

http://www.mendeley.com/research/charac ... ic-carbon/ (http://www.mendeley.com/research/characteristics-reactivity-algaeproduced-dissolved-organic-carbon/)

The important and key word is EXCESS. No one is doubting they produce doc, but no one as far as I know has measured scrubbed tanks of various designs etc. However, it really does not matter because there are easy ways to control it if required.

[Ace25]

Just had an idea that may work for the problem we are talking about. It isn't a new idea, but one I have seen tossed around every so often on forums but never seen anyone actually do it long term..

A xenia scrubber for DOCs. In theory this could work (I guess in theory a bunch of cleaner clams or scallops may do the same thing but I think those are harder to keep alive and need even "dirtier" water). On my setup of my sump, first chamber is ATS, second chamber is big and just has a skimmer and my heaters in it. I could remove the skimmer and replace it with a field of xenia and a few LEDs over them (since they don't require much light at all). You always hear xenia love dirty water, and can be easy to grow in certain tanks. I think it may work good on my setup since all the xenia would be directly after the ATS so all DOCs will have to go through the xenia before reaching the return pump back into the tank.

Anyone have any input on that idea? Great idea? Bad idea? Just trying to think of an easy/natural way to clean DOCs out of the tank and not have to rely on carbon or alternatives.

[dtyharry]

How about halisarca caerulea, a sponge. These things have been shown to consume up to half their weight every day in dissolved organic carbon but grow very very slowly. This seeming imbalance is explained by them discarding choanocytes which the other reef inhabitants can consume.
They also grow in very dark areas of the reef and so would need very little if any light!
Downside? Of course, when have you seen these things for sale!

[MorganAtlanta]

My xenia withered away after I put in an algae scrubber.

[dtyharry]

My xenia withered away after I put in an algae scrubber.

Probably because of lack of other nutrients like nitrates and phosphates, scrubbers do seem to be very good at reducing these to extremely low levels.

[turkeyfish]

My xenia withered away after I put in an algae scrubber.

Probably because of lack of other nutrients like nitrates and phosphates, scrubbers do seem to be very good at reducing these to extremely low levels.


That's weird, my xenia have gone nuts since I added a scrubber 6 months ago.

[kerry]

My xenia withered away after I put in an algae scrubber.

Probably because of lack of other nutrients like nitrates and phosphates, scrubbers do seem to be very good at reducing these to extremely low levels.


That's weird, my xenia have gone nuts since I added a scrubber 6 months ago.
I bought a Xenia frag and put it in my under powered scrubber tank with not much growth in a months time, then a few days ago I put it in my nano with a good producing screen and its doing real good now and growing already.

[Ace25]

Xenia are one of those "mystery" corals. I understand that. One minute they are doing fantastic, spreading like a wildfire, next minute they are melting away. Most SPS tanks are "too clean" to keep them alive, but that doesn't explain other tanks that are less than pristine and still have them melt away. That said, all I can do it try them and see which one my tank is, a xenia growth tank or a xenia death tank. They were one of my first corals (pom pom xenia) and did great for a year, then as I got better and keeping the tank/water clean I had more and more problems keeping them alive. Maybe if placed directly after a scrubber that will help them. I have no idea, only one way to find out and that is to try it.

I was just wondering if other people thought they would work (at removing DOCs) or am I using the wrong type of coral to do that job and there is a better alternative.

[Floyd R Turbo]

My xenias are going wild and have been since day one. I can't stand them anymore. those and anthelia / waving hand.

[SantaMonica]

What excess in the water column that GAC removed is responsible for this [brightening]? Aside from GAC or similar do we have a treatment?

I'm going by the theory that since the coral has lots food (nitrogren), the zoox are expanding to try to get more light (glucose). Both are needed by the coral.


Coral can eat DOC with no help of zoox if present. Or it can only eat DOC fed from zoox as it has no mouth to eat it from water column ?

My understanding is that DOC can be absorbed directly into the coral.


there is no possible way to get that type of bacterial diversity because we do not have the ability to do so (ie. cold water/deep water bacteria in the same system like the ocean has).

How do you know this? And why would you think that cold/deep bacteria have anything to do with tropical surface water?


Unless you employ a means to boost bacteria levels to compensate for DOCs (ie. carbon dosing) I still feel there is no way for bacteria to solve the problem in a closed system.

But people do dose. And by the way, feeding more is the same as dosing more (even dry food turns immediately into dissolved food).


Even with carbon dosing, your only multiplying the strains of bacteria in your tank, your not adding any diversity.

What about the Billions of bacteria added with every new livestock you put in?


how do they know that by carbon dosing they won't end up feeding the the bad type of bacteria because that is the majority of the bacteria in their system (ie. Cyanobacteria), causing more problems than resolving?

How do you know that when you add DOC food, which is all food, won't do the same? Why doesn't "bad" bacteria take over your body?


can you please point me to someone who has an entire tank filled with SPS corals like my picture above that I can "ask those who do" like you suggest?

They are on all the forums. I don't spend the time anymore to track it, you can post on each forum if you like. People only come here when they have a problem.


I don't know anyone that has a full tank of SPS corals and ONLY run an ATS, every one I have seen has some type of secondary filtration method to control DOCs.

You'll have to go posting on the forums like I do. Take a week, and do it. It's not their job to come to you.


When I can take a coral out of one tank that is completely brown and under 400 PAR, and place it in the other tank with the same Cree LEDs and the same PAR reading, and it starts to color back up within a week, even though both tanks have identical N/P readings, to me it really does point to one thing, DOCs.

Would be a good test if many others could do it too.


Carbon removes heavy metal contaminants and toxins

Toxins, yes, because they are organic. But metals I believe need to be combined with carbon for this to happen.


Quotes from research:

I wish more people would do this. It's fun reading studies, especially the older ones before they started using DNA.


Zooxanthellae have the ability to decrease the amount of carbon taken by photosythesis, simply by lowering the photosythesis capacity..and that is darkening themselfs.

My understanding is that darkeing is not reducing photosynthesis; it is instead increasing, via more cells which can now be seen. Zoox is always dark (dino's), but if there are not enough cells, you can't see them. But they are still in the coral's tissue.


Or too much nutrients vs. too less light..

That's my current theory. Plenty of coral food = plenty of nitrogen for growth, but relatively low light = low glucose (carbon).


I still think corals absorbing excess DOCs

Most corals excrete excess DOC that the zoox make, especially in high-light systems. As a matter of fact, entire studies (a lot of them) are done on how much of the DOC on a reef comes from the corals themselves. You can google "particulate and dissolved carbon" on the study-sites I've posted before.


You can't get much closer to the source for food (N/P) than zoox living inside a coral that is secreting food to feed the zoox.

Yes this is how it works. Although it's actually ammonia, not N/P.


The only thing you have to worry about with elevated levels of doc are massively increased microbial growth on the coral surface which literally starves the coral of oxygen. Of this there is now no doubt.

Yes, if the levels are increased. But they aren't. They are from 7 to 14 day old algae, still in the exponential growth (low DOC) phase. Besides, they are asking about browing, not death.


There really is no question on "if algae produces DOCs", the question is how much DOCs does your scrubber produce

A lot.

Algae makes all the Vitamin C, Vitamin A, Vitamin E, Vitamin B6, Beta Carotene, Riboflavin, Thiamine, Biotin, Ascorbate (breaks chloramines into chlorine+ammonia), N5-Methyltetrahydrofolate, Other tetrahydrofolate polyglutamates, Oxidized folate monoglutamates, Nicotinate, Pantothenate; These amino acids: Alanine, Aspartic acid, Leucine, Valine, Tyrosine, Phenylalanine, Methionine, Aspartate, Glutamate, Serine, Proline; Galactose, Glucose, Maltose, Xylose; These miscellaneous: Glycolic Acid, Citric Acid (breaks chloramines into chlorine+ammonia), Nucleic Acid derivatives, Polypeptides, Proteins, Enzymes and Lipids in the ocean. See the Journal of Phycology for more.


A xenia scrubber for DOCs

I personally can't keep any xenia alive. Mushrooms, yes.


How about halisarca caerulea, a sponge.

Encrusting sponges go crazy in my tank, especially the bright yellow one that is 18" long. Encrusting sponge makes up a large part of the periphyton on everyone's live rock.

Anyway, if GAC + scrubber is what some people need to for glowing sps, that's fine. Many people don't. But it would be nice to find out why this is, when it is the case.

[Ace25]

I'm going by the theory that since the coral has lots food (nitrogren), the zoox are expanding to try to get more light (glucose). Both are needed by the coral.
I do think it is an interesting theory, and I would love for someone to prove that theory, but my experience so far supports the opposite. But 1 circumstance certainly does not prove or disprove a theory, I know that. Honestly, I would love for that theory to be true because it is so easy for me to do (adding more light). I just have to turn a few knobs on my LED light at I can get 3x more than I am putting out now.


How do you know this? And why would you think that cold/deep bacteria have anything to do with tropical surface water?
I believe since it is all part of the same thing, the ocean overall, everything is connected in some way through currents. Cold water things do filter the water and it is the same water that is found on the reefs, just moved via currents. On the waters journey around the world it is exposed to every range imaginable and at each stage different things living in those environments will filter things from the water. The ocean find a balance through its huge diversity. My belief is we can not achieve that same balance by mimicking what we see in the ocean (ie, throwing rock, sand, corals, fish, and algae in a box with light over it and expecting it to behave like the ocean does). We have to employ other "alternative methods" to our filtering regime to achieve maintaining water quality like is found on a natural reef. What those "alternative methods" are will continue to change as we learn more about how the ocean works. I guess the bottom line for me is "we do not know enough about the oceans to say for certain how to maintain a slice of the ocean in a glass box." We have a basic understanding on how it works, and we try and apply that knowledge to keeping aquariums, but we are learning more and more every day and changing our perception on things. That is why I love the hobby so much though, it is an endless supply of knowledge and challenges. After your suggestion to google "reef nutrient recycling" I will admit I believe was over estimating how much the rest of the ocean does in regards to filtering, it does seem that the majority is filtered within the reefs themselves.

Question I have had: How does UV light play on the oceans bacteria? Oceans receive a lot of UV light and it can kill a lot of things, so how much does UV play in keeping the natural balance of bacteria in the ocean? I would think UV would be almost as big of a factor in bacteria population control as the amount of food available.


But people do dose. And by the way, feeding more is the same as dosing more (even dry food turns immediately into dissolved food).
That was my point, in order to keep high bacteria levels in a tank you have to dose something, food is one of those things of course. I think jnad is on to something with his suggestion. My problem may be because I overbuilt my scrubber and I need to actually make it a lot smaller in order to achieve a "balance" between algae and bacteria. I do not feed anywhere near enough for my size screen (10x13 and 4 cubes a day). Right now my tank is mainly algae driven filtration, I am trying to boost bacteria levels by dosing Dr. Tim's Eco-Balance instead of simply carbon dosing (Probiotics approach). I want to add diversity and knowing I am adding just the good types of bacteria is a plus. Carbon dosing (and yes, adding food to the tank) just increases the population of the bacteria in the tank, if the tank has more cyanobacteria than any other type, carbon dosing in that case usually just leads to worse cyano blooms because your feeding it more.


What about the Billions of bacteria added with every new livestock you put in?
If it is a minority bacteria it will most likely be out competed quickly by the bacteria in the tank. Of course some will survive, and that is one way to add some diversity to a tank. I still go back to my idea that bacteria in a reef setting is still just a slice (albeit a large slice) of the over all pie of bacteria in the ocean that makes the complete bacteria web, and in the ocean it takes all types to create a balance.


How do you know that when you add DOC food, which is all food, won't do the same? Why doesn't "bad" bacteria take over your body?
It does .. food is food.. mysis will quickly become DOCs to feed bacteria. Bad bacteria can take over your body, it is called a bacterial infection. Anthrax, Cholera, salmonella, E. coli., Tuberculosis, pneumonia, tetanus, and the bubonic plague are all bacterial infections that if left untreated could lead to death. Bad bacteria cause diseases in plants and animals that sicken or even kill them. Disease-causing bacteria can infect organisms in two different ways. Most attack the body's cells directly. Others produce chemicals called toxins (poisons). Either way, the bacteria destroy or damage cells within the plant or animal.

[kotlec]

After trying to find answer to all this theories I added one bag of high quality carbon and one bag of purigen to be on safe side and to stop coral browning.
To my big frustration nothing changed at all after one month. Blue acropora is still brown. It is not showing blue collor at all.

Any ideas are welcome.

[kerry]

Have you tried to add more light? They might be producing more zooxanthellae due to low light, this might cause them to brown. Just a suggestion???? Or maybe its the wrong light spectrum to????

[Aeros]

I just replaced two 400w Radiums bulbs at one yr old. Big difference. If light is the culprit I have now taken it out as a limiting factor in my system. I will report back in a month if my brown dying acro improves.

Last test of Phosfate read .07ppm via Hannah Checker
Ca at 400
CO3 at 14 dKH
Mag at 1400ppm

[kerry]

This could be very interesting info!!!! Maybe the scrubber is not the browning effect in the sps after all????? As a side note: does anyone have a long tentacle plate coral in their scrubber tank? I just bought one on Saturday. Here is a pic.
[attachment=0:1sg11xv3]2011-12-24_13-23-06_931fix.jpg[/attachment:1sg11xv3]

[Aeros]

This could be very interesting info!!!! Maybe the scrubber is not the browning effect in the sps after all????? As a side note: does anyone have a long tentacle plate coral in their scrubber tank? I just bought one on Saturday. Here is a pic.
[attachment=0:1pznpzju]2011-12-24_13-23-06_931fix.jpg[/attachment:1pznpzju]

That looks like fun...gia! Hah!

Related: I don't think light is the issue, but I will prove it either way.

[kotlec]

My tank is light by LED's. I used mix of cool white+ neutrall white + royal blue+ blue. This mix was proven to be exelent on other well known forum . Overall coral growth is simply mad. Browning is my main concern.

BTW what is brown mud that is collected inside filter bag when I use it ? Water seems absolutely clear , but amount of that stuff filter removes is frightening. And why it is not recommended to use filter bag in ATS system ? I use it ocassionaly for few hours though.

[Floyd R Turbo]

Just because you can't see gunk in the water doesn't mean it's not there. My water is crystal clear but I always end up with a thin layer of detritus in the sump over time, it's pretty much unavoidable. A filter bag/sock/pad does a good job of pulling this stuff out, but the reason why it's not necessarily a good idea to use a filter pad is because it creates an area for waste to sit and rot. Also, filter pads will trap copepods, some baby copepods might make it through, but most will not. Removing a pad allows them to circulate back to the display.

[kerry]

I dont use any kind of filter media at all. Its food the coral can eat if its allowed to return to the tank.

[SantaMonica]

I added one bag of high quality carbon and one bag of purigen to be on safe side and to stop coral browning.
To my big frustration nothing changed at all after one month. Blue acropora is still brown

You might note that most sps scrubber tanks do not have browning problems; only people with browning problems come to this site for answers. Using carbon to remove DOCs to fix browning is not a fix, and certainly not an established fix across many forums. Most sps scrubber tanks, on most forums, work great. So they don't come here. You only would know this, of course, if you spend time on 30 forums like I do. Only a few people, on this site, have said carbon has worked for them. Even Vanpytt is on RC now, asking what to do to fix his, since removing the scrubber did not help.


BTW what is brown mud that is collected inside filter bag when I use it ? Water seems absolutely clear , but amount of that stuff filter removes is frightening. And why it is not recommended to use filter bag in ATS system ?

It's food particles. And that's why.

[kotlec]

I am really not hanging on 30 forums and I never said I dont trust you SM. I'm not going to remove my scrubber as well as it controls P and N very nicely.
Statement that some people not have browning and few have does not help me in any way. I thing my single side 6x7 screen lit by 8 660nm leds and flushed by 600l/h for 16 hours must handle 1/10 of cube food with ease.

[Doompie]

Though About this allot..and the only real conclusion I can make is the display lights, or ca mg and str limiting..t5s should be replaced at least every 8 months, 6 even better. LEDs are still too experimental for me..I still believe the spectrum is incomplete most of the times..I've bought some frags which where all brown..after just 1 week most of the original color is already there..so i think docs cannot be the real browning issue..also I experience better SPS colors when only adding lime water as top off water..maybe the browning is because of growth limiting by a leak of ca and mg in combination with high feeding (much light and doc)..so to slow down growth, the coral algae browns..?

[kotlec]

Doompie,

I really noticed lack of Ca in my tank. I am strugling to raise it to proper region all the time. I am using DIY kalkwaser together with ATO and for raising calcium I use Tropic Marine Biocalcium. To prove it right or wrong I need to find way to rise Ca to proper levels and to maintain for some time at least. Or do you have other ideas ?

When I talk about SPS crazy growth , thats what I mean : May to December.

http://farm4.staticflickr.com/3182/5705909731_bb937acb4b_z.jpg

http://farm8.staticflickr.com/7032/6586994619_781e5b0251_z.jpg
2011.12 (http://www.flickr.com/photos/sauliusle/6586994619/)

[chrisfraser05]

WOW!!!!

I hope to see something like that one day lol

[dtyharry]

If you google some research on browning of corals it usually comes down to two issues, excess inorganic nutrients in the form of nitrogen which in aquaria is usually in the form of nitrate, in the ocean most nitrogen comes from ammonia. The other is insufficient light. The light issue is easy to remedy.
With regards to nutrients it is worth bearing in mind that even if your nitrate test kit is reading undetectable, the level is probably many times that of a natural reef, maybe ten to twenty times or even more. In such circumstances the zooanthellae algae can multiply without any help from their coral host and result in the browning that is often seen. Solution is to scrub even harder.
DOC is completely separate I believe and is to do with increased microbial growth smothering the coral and starving it of oxygen.

[kotlec]

1.Does increasing light for scrubber even more sounds right solution ? My screen was never green. It is rather yellow .

2. Does filtering out some food is better solution as I would be happy to reduce growth of SPS's as well. They already touching each other and I need to prune them on constant basis. Especially birdsnest ones.

3. Any other thing to try ?

[chrisfraser05]

The colour of the algae one I can deal with ;)

Yellow means the light is too strong for the amount of flow really. Reducing light will reduce the amount of filteration however so the solution is to increase flow :)

[kotlec]

Thats may be worth to try !