CH Low

[Adiharce]

I have been monitoring CH for a few weeks and am consistently getting 175. This is really unusual as we live in a very hard water area (lots of limestone). I think the CH was low before we entered this recent rainy season. I can't even buy calcium at a pool store here bc no one has low CH levels!
Any thoughts or suggestions?

pH 7.8 (lowering now with MA)
FC 16 (I am shocking due to recent rain and pollen dump in my pool)
CC .5
TA 110
CH 175
CYA 40

 

[jblizzle]

You can not measure the pH when the FC > 10ppm ... it will read artificially high.

You could always order some calcium to raise it if you like (Recommended Pool Chemicals), or just maintain your pH a little higher to compensate for the low CH. The CH rises due to evaporation, mine goes up about 120ppm every year.

 

[Richard320]

Switch to chlorinating with some Cal-hypo powder. (Leslie's Power Powder Plus) That'll raise CH. Down at the bottom of pool math it will tell you how much every ounce or pound will add, so you'll know how much to buy. Just use it in place of bleach until it's gone. Poolmath will even calculate the daily dose to maintain FC.