pH dropping -hello winter

[mseepman]

I have had some terrible PH issues in the last few months. I can't get it to go up. I'm dosing almost 5liters of saturated kalk per day. My Alk was crazy low before and now appears to be closer to normal, but I can't get PH up. Best it gets when lights are on full is 8.05 on my APEX. I've got two probes in different locations as a backup check. It is an issue for me as having the PH and Alk so low resulted in some cyano issues. Still trying to beat that too. I also have an HRV feeding fresh air only 10 feet from the tank. Not sure where else to go with it.