Well, now that I'm putting the output of my yeast bottle through the Via Aqua filter, the CO2 has gone up and the pH down. kH=4, pH=6.2, and the fish are looking a little mad. I was thinking about either dosing with baking soda or putting a small bag of crushed coral into the canister filter to bring the kH up a little to stabilize things. Am I asking for trouble?