Subject: Fertilizer!
> I felt my plants should be growing better so I added a very litt
> 25-10-10 fertilizer to the tank (knowing the phosphate risk).  T
> rose from 6.33 to 6.55 over the next 48 hours!  To me that means
> fertilizer aided the plants in taking up N (and thus raising the
> pH)

Why would uptake of N raise the pH.  If your plants were nutrient 
limited in some way that was satisfied by the addition of the 
fertilizer, I can see the possibility that they would suddenly 
grow faster and usse more CO2, thus raising the pH, but I've never 
heard of uptake of N raising it.

Karen Randall
Aquatic Gardeners Assoc.
Boston, MA