This thing drives me crazy, my pH never got higher than 8.0 and is always at 7.7!!, when I open windows it gets to like 7.9, and now I noticed my alk started dropping really fast, 7 DKH?????!!??!? How did it get here? Last time I got 8.5 and trust me it has nothing to do with the CO2 because I aerate the aquarium as much as possible even at night, I don't have baking soda but only chemical soda, that isn't reef safe, so I'll buffer very soon, but what's causing all that?