Kirkwood;926247 wrote: Dave,
Do you have any links you'd recommend for educating a bit on nutrient export? I'm looking at trying to enhance my nutrient biological nutrient export but need to learn a bit more before I do so.
It sounds to me like the Xenia may work more like a skimmer where it takes up nutrients before they can breakdown and convert to nitrates and phosphates... in that sense I agree that its useless...
i do however think it would be great for a FOWLR...
Not any links, but if the term "biological nutrient export" mean nutrient export via either plant, animal or bacteria type activity, I can help a bit.
Before you do anything, consider what type system you have. I have a 465 gallon SPS system, and a 100 gallon mixed LPS/Softy reef. I am nowhere near as anal about keeping the water clean in my mixed reef as I am in my 465 because my LPS and soft corals like more turbid water, so I go longer before changing our GFO or carbon, and I go really long before rinsing out filter socks, and I use a higher micron (larger opening) filter sock in my 100 than I do in the 465 as well. I also do fewer water changes in this system as well, all because I don't need to.
So, in some ways, you should try to match your nutrient export methods to the type corals you have, if you see what I mean?
And the following is just my experience and opinions, so they are not necessarily correct or incorrect.
Animal nutrient export like the Xenia fuge you posted is not export IMO. It is like using a turbo snail for hair algae on your rock. The hair algae, if it could be harvested, and removed from the system, would be nutrient export, but a sea hare or a Turbo snail eating it is just conversion into nitrogenous waste products that are still in your system and have to be dealt with one way or another.
Do not confuse nutrient conversion with nutrient export. There is a difference.
Many folks use macroalgae, like cheato, to uptake excess nutrients, then they harvest it and pull it from the system. Some folks use an Algae Turf Scrubber, or ATS, in the same way they would use Cheato, but an ATS is a bit more involved with plumbing and lighting involved, with the algae growing on a lighted plastic mesh type material and needing regular scraping, whereas the cheato would basically sit in a refugium type tank setup or by itself with water in/out and a light over it. Cheato is probably easier to maintain, whereas I am guessing an ATS might pull more stuff from the water in the same amount of time, while itself being higher maintenance because of the way it is set up.
I used an ATS for a while and abandoned it because my water clarity suffered some. Not terribly, but enough for me to not use it any more because cloudy water means less PAR getting to my SPS. You can find enough info an ATS systems on Reef Central to make you sick if you do a search on there. Just watch out for those Gurus on there that tell you at ATS eliminates the need or a protein skimmer. IMO, cheato or an ATS is just another of a multi-prong approach to nutrient export.
And bacteriological nutrient export is done basically for nitrates, like using Matrix or one of the several types of denitrators you can set up, which is not to be confused with regular aerobic bacterial activity on your LR that converts ammonia to nitrites to nitrates (nutrient conversion, not export). I use a sulfur denitrator in my 465, which uses an ultra slow flow of water through sulfur media, which becomes oxygen depleted. Not totally without O2, but enough that anaerobic bacteria start to grow, and they consume the nitrate and turn it into nitrogen gas, which bubbles off and is exported that way. In material like Matrix, the bacteria grow deep in the structure where the O2 level is low, and that removes nitrates from water as well.
Then, outside of biological nutrient export, there is
chemical and
mechanical nutrient export, which is covered by GFO, GAC, mechanical filtration, protein skimming, water changes and probably some other things I have not mentioned.
