:;f I've moved your question to its own thread for greater visibility. As for your question, it sounds as if you are getting enough CO2 gassed off overnight that you shouldn't need to worry about it. One thing you need to be concerned with is the snails. Snails do not fair well in a CO2 injected tank with the low pH values as it eats away at their shells. You will need to monitor the GH and KH levels to ensure both are at least 4 degrees/drops. Hope this helps.