Air through the bio is good. Depending on the filter material thickness,
the bacteria that do the nitrification cycle are aerobic, meaning that they
need oxygen. If the filter thickness is sufficient, all of the oxygen can
be consumed and then the extra filter material is useless. There is no such
thing as to much oxygen in the filter.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"RETRIEVE" wrote in message
.net...
I can put air into my biofilter by using a venturi tube on the inlet. my
question is it a good idea to run air bubbles through the bio-filter ? any
comments?