Top Off Water PH

[dwibier]

I was just wondering if your top off water needs to be the same PH as your tank? I have been having a little bit of a problem with my PH. I have to add about 1 gallon to a 35 gallon tank every day for top off. My top off is usually around 6.2 pH. Should I use a buffer to raise it? My tank ranges from morning to night from 7.8 to 8.2.

[Randy Holmes-Farley]

If the top off water is purified (like RO/DI) then it makes no real difference what the pH reads. Kits and meters won't read it correctly, and even if they did, there is not much buffering in it to impact the pH of the tank.

I would not use any buffer to raise it. If you want to raise the tank pH, there are several ways, the best of which may be to put a bit of lime into the top off water.

This article should help:

Low pH: Causes and Cures
http://reefkeeping.com/issues/2004-09/rhf/index.htm