Re: Ammonium

>Plants generally will not use nitrates due to the amount of energy
>required to extract nitrogen from the compound.  They much prefer
>ammonium as the nitrogen is less tightly bound.  By removing the
>biowheel, there are less nitrifying bacteria to convert ammonium and
>the conversion goes slower, giving the plants a better shot at using

Help. Where does ammonium come from? I thought ammonia was what the fish
secrete. If so, something must first turn ammonia into ammonium ... Where
does that something come from? TIA.

A related question: when one has a biofilter in a heavily planted tank,
would the bacteria and the plants be in competition? If so, who gets what
first? My guess is the filter gets the ammonia first because it's puming
the water through while the plants stand around waiting. Thus, the plants
are more likely to get only nitrates--which we now know they have a harder
time making use of.

Greg. Tong
San Francisco, CA, USA
gtong at sirius_com

"Every infinity is composed of only two halves."