Raising pH by water change??

[tyh]

is it possible to raise the ph of my tank by doing a 20% water change?
say from 7.8 to higher??
7 gal nano
HOB filter
18w 10k and 13w acts
mainly softies and LPS

 

[Anonymous]

It's possible, but a buffer would probably work better.

 

[danmhippo]

There is another possibility that your pH is lower, CO2 dissolved in the water.

Test: Take a small cup of tank water, place a small airstone in it and aerate the water for 3 minutes. Let the water sit for another minute or so, and test pH. If pH is higher after aeration, then you may have high CO2 content in the tank. Try directing a powerhead towards the surface to dissipate CO2.