CO2 and Ph effect?

[cyber_ecco]

Can you guys tell me how much of a PH drop can I expect once I add CO2 into my tank? I will have 2 X 65W Pc lighting on my 32 gallon. I'm wondering cause my PH seems fixed at 7.2 right now even though my water out of the tap is 6.0 and I can't figure out what is causing it. I would suspect its the gravel...since the only other things in there are 2 pieces of driftwood. its a pretty fine granule size black sand mixed with Laterite. Besides that I have a Fluval 204 with Carbon and some Nitrate Sponge stuff that came with the filter when I bought it. I would ideally like to get the PH down to 6.5 and have it stable around there. Will adding CO2 do this for me? I'm planning to make a planted tank anyway...so hopefully this solves my problem. Thanks.

Gord.

 

[emoore]

How did you test your pH out of the tap? You have to let the water sit for 24 hours before testing it. What is your KH and GH? Once you know your KH and pH you can get the CO2 amount.

 

[daveedka]

I would suspect your tap is high Co2 and when it off gasses it jumps up.
7.2 typically indicates a low KH so you definately will want to know your KH level before you start injecting. If you do not have enough Kh Co2 can crash the pH pretty quickly. Most folks reccomend a minimum KH of 3 degrees (54 ppm) for co2 injection.

Dave