Re: water changes

Steve from breedofish at aol_com has raised an interesting question that deserves some 
discussion.  I would have to agree that water in a well planted tank probably does not have 
to be changed as frequently as that in a tank relying only on a biological filter for cycling of 
organics.  However, it has been my understanding from reading many postings on this list 
that aquatic plants utilize ammonia as their primary N source, not nitrate.  Consequently, 
over a few weeks time the nitrates may still build up in concnetration.  You would 
probably have to severly neglect your plant tank for many weeks to reach a toxic level of 
nitrates, but it's better to be safe, right? Anyway, just my two cents worth.

Robb D. VanPutte
Dept. of Biology
Texas A&M University