You need to check and see if your home is causing a CO2 build up. The fastest way to check is open a window near your aquarium and see if your PH goes up. If it does then you can benefit from a scrubber, or a line to the outside plumbed to your skimmer.
Worked for me.
I tried everything to raise ph, and finally broke down and got the BRS $32 scrubber and the shopmedvet Soda Lime (11.99/3lbs -will fill canister 2.5 times). Wish i had done it 6 months ago! Raised my ph from a constant 7.8 to 8.3 by the next day. I’ve had it running for two weeks now and only exhausted 20% of media in canister.
I rigged the intake to the scrubber cup for humidity and to recycle air for longer media life ($7 bucks for tube and fittings).
So far so good! I recommend!