Metrics of success

[sublime]

So, I have been running without a skimmer and using the ATS for 5 weeks now with only one water change. I tested the water again last night still have undetectable nitrates and phosphates. (Before I started running the ATS they were also undetectable.) I clean the screen ever week as directed. One side of the screen seems to have the "black and brown" algae growing. I think I need to add more light, the water flow is above minimum recommendations.

I have noticed one colony of zoanthids started not opening up completely in the past week. I changed the activated carbon last weekend and did a 25% water change. They opened up a little more but not completely. I am not convinced that this issue is related to the changes I have made to the filtration system but I also cannot rule it out.

My question is this: Are there other metrics of success to consider besides nutrient levels we can test with our standard kits that would lend itself well to a more complete understanding of the quality of the water? In other words, besides nitrates and phosphates are there other considerations that should be observed when using an ATS vs a skimmer? If I am still not clear, in very basic terms, should I be concerned about anything else going on in the system that could adversely affect the tank inhabitants from this switch besides nitrates and phosphates?

All the SPS and LPS are doing fine, it is only one colony of zoas that is all of the sudden not doing well. However, I know they sometimes just freak out for no apparent reason.

Brandon

[SantaMonica]

I don't even measure N and P anymore. I can tell what's going on from looking....

Diatoms on back wall: Nutrient spike.
Glass growth is brown: Higher nutrients.
Glass growth is green: Lower nutrients
Stoney and coralline growth: P is low.
Fast stoney growth: P is low and food is high.
Mushrooms really expanded: Higher nutrients.

[dtyharry]

I think if it is only zoos causing a problem and everything else is okay, the problem is with the zoos and not anything to do with your water. The sps in particular are far more sensitive to water conditions.
I am sure you already know this but skimmers and scrubbers just work on completely opposite sides of the filtration scale. Skimmers remove the waste before it breaks down into nitrates phosphate etc, scrubbers wait for the waste to be broken down, eaten, absorbed etc and then absorb the nitrate and phosphate as it is produced.
Santa will groan now but excess algae has been shown to produce elevated levels of dissolved organic carbon (doc) on natural reefs which causes an increase in coral mortality. To date there have been no measurements taken in aquaria because the equipment costs a fortune so we do not know if this could be a factor in some people's tanks, some are convinced of it, others not.
I think you need to wait longer before a judgment can be made, it is early days.

[Vannpytt]

If you are experiencing this, and softies and lps starts to be affected in a few weeks, beware. You will have 2 options. Increase feeding drastically or change filtration. Either way you will have more problems to troubleshoot.

[sublime]

dtyharry: So, am I to understand that DOC is one other metric that could affecting the tank? What about ORP?

Vannpytt: Can you elaborate some on your statement please?

SantaMonica: Do you know of any other metric that could be measured to understand more about what is going on? Also, my real question was never really answered... Besides N and P, are there other things that matter when comparing a skimmer to a scrubber? dtyharry mentions DOC, are there others?

Brandon

[Vannpytt]

No, I can't, but I had the same thing. Algae growth distributed in sand and on rocks, large scrubber standalone filtration overfimensioned, no nutrients detectable. First my softies died, then the zooas and lps following my sps fading out and stn'ing en mass. Tjos got worse and worse. Read my threads. Changed to a bubbleking 300 on a 170g system and 4 weeks or so later with pellets and no scrubber colors are comming, polyp extension is excellent and i feed less. Sps grow very good.

[SantaMonica]

algae has been shown to produce elevated levels of dissolved organic carbon (doc) on natural reefs which causes an increase in coral mortality

No it hasn't. Natural levels of algae produce natural levels of Vitamin C and Amino Acids for coral growth. Not elevated levels.

By the way, it has been discovered that elevavated levels of water has been shown to kill corals. And fish. If the H20 percentage is high enough, everything is killed.

Besides N and P, are there other things that matter when comparing a skimmer to a scrubber? dtyharry mentions DOC, are there others?

Only coral growth. What else matters?

You can't measure Vitamin C and Amino Acids (I mean, DOC) by the way.

Algae growth distributed in sand and on rocks

A very weak scrubber, in this case, leaving tons of nutrients in the water.

[Ace25]

I think we all need to get out of the mindset of comparing DOC levels in the ocean to DOC levels in a tank. There is no comparison. The ocean obviously has all the tools in place to make sure DOCs are at a sustained (safe) level (excluding high pollution/run off areas near the coast which leads to red tide but that is man made issues causing that), where as in a glass box, we have maybe 1% of those "tools" at our disposal to keep DOCs in check. Also, with all the talk on here lately about DOCs, I think others may be getting the impression they are a major factor in a lot of different problems, and I really don't think that is the case. It is a factor to consider and keep in mind, but on a check list of top 10 things that could cause problems for corals in a tank, I would probably place it at #10. There are many other variables that can cause issues more often, and are things you can test for, unlike DOCs. I do think DOCs are an issue in my tank, but that is after going down the list of all other possibilities first and ruling them out.

Good question about ORP. I know skimmers can aerate the water much better than most other items we use on our tank (aerate is different than oxygenate, which is what a scrubber does). Aerate forces the bad stuff out of the water and speeds up gas exchange where as oxygenating just means adding oxygen back into the water. Aerating does some oxygenation via gas exchange, but it doesn't force oxygen into the water like algae does by consuming CO2 and releasing O2. I haven't checking my ORP in so long I am now curious what the levels are. When I ran an Ozone generator I kept it around 400. It would be curious to see what effect running an ATS without a skimmer and with a skimmer does to ORP levels, I would suspect the one with the skimmer would have higher ORP (which is usually a good thing since low ORP is much more common than high ORP in a tank). Obviously too much of anything can be fatal, even too much oxygen.

Santa Monica's comment reminded me of the spoof "Ban dihydrogen monoxide" poll that goes around during election times, stating how many people die from this deadly chemical (which if you haven't guessed, dihydrogen monoxide = H2O).

When comparing a skimmer to a scrubber, it isn't really a clear cut thing. They both overlap some on the job they do, but then each also does completely different things in a tank, so comparing a skimmer to a scrubber is like comparing a bicycle to a train, both are modes of transportation, but each have different methods of doing so. A scrubber does not remove Calcium or other minerals out of the water, where as a skimmer primarily removes calcium and then behind that other elements, removing "bad stuff" out of the water is actually low on the list of things a skimmer does. Just because you have black stinky skimmate doesn't mean it was bad to have in a tank, I would put $ on 70% of the liquid in a skimmer collection cup is actually good stuff that should have remained in the tank. This to me is not a good thing. On the flip side, skimmers remove some DOCs (lipids, oils, and other stuff) that can be considered bad in a reef tank at elevated levels. Studies show about 30% of DOCs in a tank are hydrophilic and can be removed via bubble fraction, remaining 70% stays in the water because they are hydrophobic and can not stick to bubbles to be removed, where as with carbon 80% of DOCs can be removed, meaning if your goal is to remove DOCs from the tank, carbon is by far the most efficient method to do so, but can be very costly long term and not safe to use with certain types of fish. A scrubber only creates DOCs, it does not remove them at all, and without a means to control DOCs in a tank (either skimming or carbon) I do believe long term use of a scrubber only system with limited rock and corals in a tank can eventually lead to severe issues. How long until a tank reaches that point differs greatly since every tank is different.

So bottom line, there really is no way to compare a scrubber to a skimmer because they do different things. A better comparison is to compare a scrubber to a refugium, that is the same thing (using algae to clean the water in a tank).

Question, did you remove any equipment when you added the scrubber to your system? Another thing, I don't really agree with but so many others swear by it so I will repeat it, Iodides help zoas. People that dose Iodides (not iodine, iodides are a safer version of Iodine) seem to think it really helps zoas open up and spread. I have always gone by the rule of "don't add anything to the water than you haven't tested for before hand" and anytime I test Iodine levels they come back saying they are equal to ocean levels, so to me that tells me not to dose any, but others do and report good success. Take it for what its worth... which is hearsay.

[dtyharry]

algae has been shown to produce elevated levels of dissolved organic carbon (doc) on natural reefs which causes an increase in coral mortality

No it hasn't. Natural levels of algae produce natural levels of Vitamin C and Amino Acids for coral growth. Not elevated levels. .

Conveniently missed out the word EXCESS from my excess algae quote there Santa again and yes it has been shown to cause coral mortality by indirectly starving them of oxygen through increased coral surface microbial growth.
Secondly, you have the habit of saying that doc is amino acids as if doc is a simple substance whereas in fact there are many hundreds if not thousands of varieties, most of which are not amino acids.
Thirdly, do not let Santa make you think that hair algae does all the filtration on a reef. Physical levels of such algae are very low on a healthy reef due to herbivorous fish grazing, only unhealthy reefs become algae dominated.
The primary algae in the ocean is phytoplankton of which aquariums have virtually zero.
Most of the water quality experienced on a reef is due to the sheer volume of water being transported there every day as Santa once mentioned, can't remember the name now, something transport, ackman, eckman?

[jnad]

Hello!

I dont know or have the experience to say if there exist an DOC problem when using algaescrubbers, but if there is a Doc problem maybe there is a simple solution for us algaescrubber users:

When you set up an aquarium so maybe it pays to build a scrubber with a smaller size so that there is less algae mass in the system. Follow the new size / feeding guidlines from the SM, but think That you wish too feed a little bit less. In this way, it might in the aquarium be more like the balance between algal mass and water as it is in the sea.

Another aspect of this is that we all want green growth around the screen and a too large scrubber will then be very costly in terms of how much food you may have to purchase to achieve this growt. Is it really needed to feed a normal stocing 50 gallon aquarium 5 cubes a day or is it enough with 2 cubes?

Just some thoughts

jnad