Using algae to bind nutrients

[Janelle12]

"In our tanks, P has a relationship with the rocks and any other Calcium based material. P will bind with Ca quickly and in some ways our rocks are the primary sink. Using algae as a nutrient "sink" is problematic with Ca based rocks and sand. Algae would work better in a non-ca based environment, but since we use CaCO3, then it is like having two sink in which you are banking P. The rocks are normally the better of the two at getting P. So when P becomes available it would normally sink into the rock first. Bacteria can then cleave off P in search for carbonate and P can be re-released. Here is the problem. For algae to survive and be harvested, there must be abundant P source because some will go to the rock and some will go to the algae. So we are forcing ourselves to add more P into the system to support the algae that what the algae will actually absorb (and hopefully be caught by our hands and removed). The end-stage of this is that to keep algae going, there needs to be ample P but the rock will eventually have their fill and bacteria will begin releasing P from the rocks at a faster rate than it can absorb. Combine this with algae's constant uptake and release, and the hobbyist feeding/bioload, you are looking at a euthrophic system whereby it can no longer support calcifying corals. This is called "old tank syndrome" and in the Smithsonian image with the algae growing all over everything else, that is the stage where thing start collapsing. You have a lot of P with very little place for it to go. And no, not even harvesting certain types can keep up. "You have to remember that algae is constantly dying, shedding cells, bacteria is constantly attacking it, and it has to expel its own wastes. An environment for algae is not an preferred environment for many types of SPS corals we keep. It is like growing a rat/cockroach population to clean your house. Humans do not do well when these other organisms are populating in large numbers. A few, we can handle but signs of their population increasing suggest that there is a "nutrient" problem." futuredoc , post no. 1055 on reefkeeping made easy thread on the reef tank site ( he is referring to the sps tank failure at the Smithsonian when they used these methods)

[Wade]

Would the remedy for "old tank syndrome" then be to replace your rock? It doesn't sound like the substrate has all that much to do with this is problem. It would seem to me that the key indicator would be continually detectable amounts of P in your system no matter what you do to get rid of it. Is there anyone on ARC that has experienced "old tank syndrome" as described above and if so what did you do to remedy the situation?

[Bpb]

I may be way off mark here, but from seeing enough spectacular tanks with colorful sps, no gfo reactors, no refugiums, old rock, and shallow sandbeds; there's one thing in common. Heavy load of herbivores. Phosphate enters the tank via food...algae and rocks soak up phosphate...tangs (and others) pick rocks clean of algae...herbivores grow and eliminate waste...algae and rocks re-uptake phosphate (and other wastes)...and so goes nutrient recycling.

The science here may be a bit off, but havin seen it first hand it seems to make sense. Phosphate continually bound up in tissues instead of in the water column.

[Wade]

The only Tangs that are rated by LiveAquaria for a minimum 70 gallon tank (I have a 72g bowfront) are the bristle tooth tangs all of which are recommended to only have one per tank. What other fish are good herbivores?

[Bpb]

Lawn mower and starry blennies are pretty good from what people have told me who keep them. Mollies are good as well but in my tank they generally stick to the soft biofilm type algae. They haven't messed with the green hair algae. I think you could get away with one of those tangs in your tank. Some purists would disagree, but one by itself would be fine I would think.

[bige]

Lawn mower and starry blennies are pretty good from what people have told me who keep them. Mollies are good as well but in my tank they generally stick to the soft biofilm type algae. They haven't messed with the green hair algae. I think you could get away with one of those tangs in your tank. Some purists would disagree, but one by itself would be fine I would think.

Agreed. Mollys are good at keeping the macro trimmed but won't touch hair algae (in my experience). You can keep a school of them if you like. One is fine too. They are fun to watch. Have a fw fish personality. Meaning they stay out cause they aren't familiar with sw dangers. A good dither fish.

[bige]

And acclimation is simple. Some say an hour and some do longer.

[Planeden]

I wonder if you can acclimate silver dollars? The are good herbavors.

[Wade]

How would a Powder Blue Tang do in a 72 gallon? It's rated for a minimum of 125 g on LiveAquaria, but I don't know if that means that it just won't be happy in a smaller tank or will just not grow as big as it could. The 72 is 48" long so it should have a bit of swimming room.

[Bpb]

Wouldn't do a powder blue. Those get fairly big and are fairly delicate. The bristle tooth is the only tang id bother with in any tank less than 6'

[Wade]

Fair enough. There's 4 or 5 different kinds of them and they're all good looking fish.

[bige]

Just an FYI, the bristle tooth tangs scrape rocks and tend to stay away from the larger algaes. But I really like yellow eye kole tangs.

[Wade]

Yeah I was including them with the bristle tooth (in my head). They're good looking fish. I'm leaning towards either one of them or the two spot with the white tail bringing up the rear.

[Timfish]

Considering Dr. Adey's success growing various species of stoney corals with his "Mesocosim" methodology I would not consider it a failure. Delbeek and Sprung "The Reef Aquarium" has a good discussion of Dr. Adey's approach on pg 371 - 385. Pictures on pg 375 show one example of a Acropora cervicornis colony quadruple in 6 months.

This article provides a good describtion "Old Tank Syndrome": http://www.advancedaquarist.com/2006/10/aafeature There are other things tha build up in our systems besides phoshpate and nitrates. I have seen marked improvement in corals after a tank move even though no new rock of sand was added so while there might be an issue with existing rock or sand it's clear to me it's not a factor in every scenario.

I think it's important to remember reef systems are high nutrient systems (Charles Delbeek, Coral, Nov - Dec 2010, pg 127) and corals aggressively remove nutrients from the water column to fed their symbiotic dinoflagellates. Trying to stop algae growth by reducing phoshates and nitrates can also stop and even kill corals if reduced to low. Alternatively systems with healthy coral growth can have surprisingly high phosphate and nitrate levels without have a nuscence algae problem.

[Janelle12]

Im interested in finding a good balance of nutrient rich (for good coral growth...in particular softies...) and yet not so high in nitrates or other algae-nuisance-causing compounds. Thoughts?

[Timfish]

You do need to monitor water parameters but don't chase numbers and it is possible to drop nutrient levels to levels that will cause slow growth, bleaching and even death in corals. Feldman et all, has 8 very interesting research articles on AdvancedAquarist.com looking at skimming and GAC and how Total Organic Carbon, TOC, and bacteria populations are meditated by them. Also keep in mind the terms "SPS", "LPS" and "Softies" are not valid scientific terms and have no relevance to the husbandry requirements of a species. Lookng at Veron's "Corals of the World" many of the different Acropora species live in mutually exclusive habitats and Poccillapora damicornis is found in mangrove swamps. Bourneman points out in "Aquarium Corals" Stylophora species show much better growth rates when hosted by damselfish. In my opinion your best odds of successs will be to network with other aquarists. (Like on ARC. ) See how other aquarists have dealt with problems and equally important see what environmental conditions are needed for different species and how different environmental conditions influence the same species (some look the same under a wide range of conditions, some may look very different and some are not very tolerant of differing or changing conditions).

A final point is while phosphate and nitrate are often the culprit's with nusceince algae problems it is not a direct corelation. The following video is of a filterless skimmerless system with phosphate levels around 3 ppm about 60 - 100 times what it should be. Now to be very clear I DO NOT ADVOCATE HIGH PHOSPHATE LEVELS but want to show the problem is unfortunately more complicated than simply having to much phosphate or nitrate. Since this video was taken the phosphate level has dropped to less than 1 ppm currently with just water changes and syphoning out Xenia.

I noted in the thread referenced in the first post some comments about refugiums. This sysem is one I set up with both cryptic and lighted refugia (no skimer). It took three years for the phosphates to build up to .11 ppm. While any system will work the combination seems to me the most stable and fairly easy maintenance wise.

[Wade]

Is there a difinitive chart that tells you what size aquarium is need for each kind of fish? I've been using LiveAquaria's recommendations, but Saltwaterfish.com, PetCo, etc. all say different things. Who's the authority?

[Bpb]

I tend to side with live aquaria.

http://www.reefcentral.com/forums/showthread.php?t=1946079

This is helpful also. Mods sorry if this link is against the rules. Please delete if it is.

[Timfish]

. . . Who's the authority?

Nobody is. Dr. Scott Micheal, "500 Marine Aquarium Fish" lists something different also. The simple answer is be super conservative until you can recognize behavioural problems with fish (not all of them include fin damage). An aquarist also needs to give very serious thought to the extent they are willing to tear their tank apart to deal with behavioural issues. I don't have a problem putting 4 or 6 medium sized Yellow Tangs in 55 gallon tank since I KNOW as they mature and grow I can relatively easily remove them AND I KNOW I will have homes for them. Totally different story in a 120 gallon where by the time Yellow Tangs are going to start trying to kill each other off it's going to do a lot of damage to the corals that have grown up to tear apart the tank to deal with them, I would be hesitant to do more than one per species and maybe not more than one per genus. Too many aquarists are unrealistic with their long term plans and end up torturing fish unnecessarally with "pie in the sky" dreams of bigger tanks.

[Wade]

Most everything I've read recommends only one tang per tank so that's my plan. If I can get a species that will be happy long term in my 72, then all the better. It appears the bristle tooth is my best bet. I don't see a bigger tank anytime in my future unless we move to another house.

[bige]

In your 72,I would agree. Better safe than sorry.

[subsea]

Would the remedy for "old tank syndrome" then be to replace your rock? It doesn't sound like the substrate has all that much to do with this is problem. It would seem to me that the key indicator would be continually detectable amounts of P in your system no matter what you do to get rid of it. Is there anyone on ARC that has experienced "old tank syndrome" as described above and if so what did you do to remedy the situation?

Wade,

I do not consider the fist post an accurate description of "old tank syndrome". Neither do I consider live rock to be a phosphate sink. In nature, a dominant species will triumph. Old tank syndrome is the fulfillment of that reality. As competing species win out, they dominate the competition. Without interference, instead of a bio diverse ecosystem, old tank syndrome produces a monotone landscape. Your observation about continuous detectable amounts of phosphate in the water column is the key to understanding that there is a problem.

To better understand the complexity of phosphate, it is necessary to separate phosphate into organic and inorganic. Inorganic phosphate dissolves in the water and is measured as ortho phosphate. Organic phosphate is bound up in detritus that accumulates in the sandbed. Terrestrial plants can uptake organic phosphate thru enzyme action taking place in the soil. Primitive cynobacteria in our sandbeds uptake organic phosphate thru enzyme action. Randy Holmes goes into great detail about a bio feed back loop that these primitive bacteria use to complete the process.

Imagine that, smart bugs.

Patrick