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Re: Biofilter et al

Interesting debate on biofilters in planted tanks.

Two observations.

1) The concept of plants "getting to NH4 before nitrifying bacteria" is a
little bogus, IMHO. Plants don't chase after NH4 any more than bacteria do.
NH4 from fish and decomposition diffuses into the water and is available to
all takers equally. Water movement helps distribute it. A molecule of NH4
will be consumed by whatever consumer it comes in conact with. I would
venture a guess that bacteria, in general, have a better chance of consuming
NH4 than plants because there are more bacteria and they are everywhere.

2) Maybe biomedia offers an attractive substrate but so does gravel and the
sides of the tank and filter tubes and everything else in the tank. An
experiment was done some time ago that showed about 25% of the biofiltration
takes place in a typical filter and the rest takes place everywhere else in
the tank. Removing the filter won't stop the bacteria from "competing" wth

Use biofilters, don't use biofilters, you won't affect plant growth much.

George Booth in Ft. Collins, CO (gbooth at frii dot com)
  The website for Aquatic Gardeners by Aquatic Gardeners
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