Today I tested CH, and it was 275... while I like that number, it's down from 300-325 from a month ago.
A bit of background - this is a new pool/plaster, and I've been working through a scaling/gray mottling problem (thread here) and trying to get the PB to come and take a look (but that's another post for later).
What I've been doing is keeping CSI under 0 as much as possible, by keeping the ph under 7.6 and TA at 70-80. Is it normal for a new pool to see CH decrease over time, or is that specific to my keeping CSI on the negative side? Or is it just due to a lot of rain in the past month? My CYA has stayed the same, or even increased a little (now 50, previously 45).