CO2 advice

[wil0311]

I used to have ph at around 7.8 to 8.0 because of my calcium reactor but now after adding cheato to my 20 gallon sump and keeping the lights on 24 hours a day, my ph now varies between 8.1 at night and 8.3 daytime. I can see the change on my ph meter within an hour of turning the lights on. I have cheato about the size of 2 basketballs in the sump and it really worked well for me.