+ Reply to Thread
Page 1 of 10 12345678910 LastLast
Results 1 to 10 of 100

Thread: Browning of corals

  1. #1

    Join Date
    Dec 2010
    Location
    uk scotland
    Posts
    47

    Browning of corals

    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

  2. #2
    Banned
    Join Date
    Apr 2011
    Location
    USA
    Posts
    940

    Re: Browning of corals

    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.

  3. #3

    Join Date
    Dec 2010
    Location
    uk scotland
    Posts
    47

    Re: Browning of corals

    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.

  4. #4
    Administrator
    Join Date
    Oct 2008
    Location
    Santa Monica, CA, USA
    Posts
    10,325

    Re: Browning of corals

    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).

  5. #5
    Banned
    Join Date
    Apr 2011
    Location
    USA
    Posts
    940

    Re: Browning of corals

    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!

  6. #6
    kerry's Avatar
    Join Date
    May 2011
    Location
    USA
    Posts
    1,406

    Re: Browning of corals

    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!!!!
    150G. Reef/Mix
    125G. 3 Regular Oscars/1 Jack Dempsey
    75G. 20+ Africans
    40G. Fish/Reef. Algae Scrubbers on ALL my SW
    10G. SW Fish/Reef.
    10G. SW Hospital/new fish quarantine/pod breeder tank
    6 stage RO/DI system 200 GPD.

  7. #7

    Join Date
    Dec 2010
    Location
    uk scotland
    Posts
    47

    Re: Browning of corals

    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

  8. #8
    Administrator
    Join Date
    Oct 2008
    Location
    Santa Monica, CA, USA
    Posts
    10,325

    Re: Browning of corals

    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.

  9. #9
    Banned
    Join Date
    Apr 2011
    Location
    USA
    Posts
    940

    Re: Browning of corals

    Quote Originally Posted by SantaMonica
    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
    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.)

  10. #10

    Join Date
    Jan 2011
    Location
    UK
    Posts
    137

    Re: Browning of corals

    Quote Originally Posted by SantaMonica
    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.

+ Reply to Thread
Page 1 of 10 12345678910 LastLast

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts