# Seachem matrix



## TKC747 (Dec 5, 2008)

*MalawiLover wrote* in another thread


> NitrAte is the end result of the nitrogen cycle. The only way to remove it is through water changes.


Does anyone use seachem Matrix? Supposedly this stuff, usually in a canister filter will process the nitrAte with anaerobic bacteria stuck in the pores of Matrix. Seachem has a version with smaller granularity called "de nitrate" which suppoosedly does the same thing with lower gph

Is Matrix and "de nitrate" useful in your experience? Do you have to do less water changes? I can't imagine that you don't have do ANY water changes

Any thoughts and experience with this stuff is appreciated

Thanks


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## Fishbulb2 (Sep 23, 2008)

I have not tried Matrix yet but I have used de*nitrate for a long time. I tend to use de*nitrate in denitrators so these have very low flow rates, like a drop or two per second. In this application it works fine, but I have not tried it in any other type of filter. It has a max flow rate of 50 gph.

I think Matrix is a very interesting idea but I would image you need to use it very carefully to get the full effect. The idea of matrix is taken from live rock that is used in reef tanks. Essentially, all of the aerobic bacteria colonize the outside of the rock and utilize all of the O2 before it makes it's way deep inside the rock. Here anaerobic bacteria process the nitrates and release N2. This is something I always thought was drastically missing in the freshwater community.

Set up with just live rock, in the fashion described above, most reef tanks can be quite heavily stocked and have very low to no nitrates present. Live rock can be that efficient. However, it's really easy to ruin the whole process. As soon as you add a sump with efficient wet/dry filtration, the nitrates soar. Think of bioballs or bio-wheels. These devices are so efficient at colonizing aerobic bacteria, that it will all grow there and not on the live rock. Probably one of the biggest advancements made on reefcentral (yes i'm an addict over there) made over the last 5-10 years has been to advise everyone to remove their bioballs and wetdry filters. The latest trend along these lines is to swap and clean out their filter socks every day or two to prevent them from colonizing with aerobic bacteria. The filter socks are then cleaned and reused. All of this is an effort to couple the aerobic and anaerobic process to the live rock and remove it from competing sites. Google "Nitrate Factory" and you will probably find a hundred links to Reefcentral threads describing the phenomenon of greatly lowered nitrates with just removing wet/dry filtration in the presence of live rock.

What does this have to do with seachem matrix? Well now we know the theory behind it. I think it will definitely not work if you give the aerobic bacteria a more suitable place to colonize and grow (like a wetdry filter of any sort). Number 2, I worry about how small the actual Matrix pebbles are in comparison to actual live rock. Is the center of the matrix rock really spatially far enough away from the surface to have achieved anaerobic conditions?

If I were to try matrix in a serious attempt to remove nitrates and get good biological filtration off of it, I would remove any wetdry filtration that I thought could outcompete the matrix and I would try the largest rock size they offer (Matrix Pond would be my first choice, then Matrix, then De*nitrate). Of course, you could also just try dead live rock in your sump and see if you get a reduction of nitrates that way.

Good luck. I think that this is a very interesting product but I doubt it's being used correctly by most freshwater enthusiasts. We have a lot we can learn from the reef guys and think this product is a step in that direction.

FB


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## TKC747 (Dec 5, 2008)

Thanks, Fishbulb,

I think I am in over my head, someone said it was good for biological filtration so on impulse I bought 4 liters without doing the research. your post will definately help me apply it in practice :thumb:


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## Fishbulb2 (Sep 23, 2008)

Just to be clear, I don't think in anyway did you make a mistake. Worst case scenerio, it will work like all other biological media and help convert ammonia and nitrites into nitrate. Also, it's well priced compared to other media like Eheim Substrat Pro. So you got a filter media regardless. It's just that extra mile of denitrification that I think is the tricky, not entirely confirmed in practice, part of the equation.

FB


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