> 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
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.
Aquatic Gardeners Assoc.