Fresh Air

[hobogato]

one way to check to see if it is CO2 buildup is to take some water from the tank and test the pH. then, put an air stone in the sample and let it bubble for a while (15-30 min) and test the pH again afterward. if the pH goes up, you are getting a buildup of CO2 in your tank. it may be caused by the need for fresh air in the space around the tank or it may be caused by a need for better gas exchange for the tank. i used to keep an air stone in my sump to keep DOC DO (dissolved oxygen) levels up and encourage better gas exchange for this exact reason.