I recently added a pressurized CO2 system running at 1 bubble every 3 seconds in a medium to heavily planted 9.2 gallon tank. CO2 is on timer going on an hour before lights go on and off an hour before lights go off. Fish and shrimp are normal and no signs of stress or gasping for breathe. Massive amounts of pearling on plants! My question is when is the best time to do a water change? During the day when CO2 is running or at night when it's off? Does it really matter? Any insight is appreciated. I condition the water with prime and age it for a min of 24hrs. Thanks everyone!