# Too much Bio-Media?



## snickle (Apr 8, 2007)

I have a 90G with built-in overflow feeding a wet/dry filter (with a massive bio-media area). The tank was well-established before going planted.

The stocking load has not changed significantly since I went planted.

Doing some testing on frequency of water changes, since the tanks has been planted. I notice, that if I let it the Nitrates climb to about 40ppm and then level off. I am assuming the plants are consuming the nitrates at that point.

I was reading Diana Walstad's "Ecology of the Planted Aquarium". She suggests that plants prefer Ammonia and Nitrite to Nitrates as a source of Nitrogen. And suggestions reducing the amount of bio-media in the canister to allow the plants to receive more of the simpler form of Nitrogen.

If it is true that the bacteria can out compete the plants for the raw forms, and then the plants need to breakdown the nitrate, then my wet/dry setup is probably making it harder on the plants.

Would it be worth removing the a large percentage of the bio-media and let the plants get more of the raw nitrogen?

Thoughts?


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## dwalstad (Apr 14, 2006)

snickle said:


> Would it be worth removing the a large percentage of the bio-media and let the plants get more of the raw nitrogen?
> 
> Thoughts?


My advice would be to first remove 1/2 of the bio-media and see what happens. At some point, you may be able to remove all of it if you want.

Factors to consider:


plants are plentiful and growing
the substrate contains mulm/soil/organic matter (some of this gunk will actually contain nitrifying bacteria)
tank isn't grossly overloaded with fish
you maintain some water circulation

Official "Bio-filtration" (via a filter) seems irrelevant in a planted aquarium. Removing the filtration media may stimulate plant growth somewhat and help in reducing nitrate levels. The proof is in the pudding!


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## snickle (Apr 8, 2007)

I run about 400G per hour of filtration and plan to keep up with the mechanical and my thought was to eliminate some, but not all of the bio-media.

I have about a cubic foot of tightly packed pot scrubbers as bio-media.


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## DonaldmBoyer (Aug 18, 2005)

Wow, Snick! You got it right from "The Legend"'s keyboard! HA! I haven't seen that here, so count yourself lucky!

I would say that bacteria could easily out-compete plants for Nitrogen. There are billions of nitrifying bacteria in your tanks, and the combined surface volume for those bacteria is huge compared to the plant roots' surface area for absorption of nitrogen. I would say that you could easily remove most of your bio-filtration if you don't have a huge amount of fish without any problem. Another point is that these nitrifying bacteria are also in your substrate, your filter, on your plants, etc., etc.; not just in or on your bio-media!!

Personally, I don't keep any chemical or biological filtration on my filters anymore. I have a very light fish load in my 40G and it is heavily planted, and even a fairly high fish load in my 100G and I've had no problems. I stress that I did give the tanks plenty of time to establish their bacteria population first, BEFORE I removed the bio and chemical filtration. After a while, though, you don't really need to have either one IF you have a heavily planted tank.


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## snickle (Apr 8, 2007)

Thanks all. I am replacing my substrate this weekend, so I will give the tank a few weeks to settle and then try removing about 75% of my bio-0medai and do regular testing.


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