CH levels on the rise


Silver Supporter
Apr 1, 2021
Kansas City, MO
Pool Size
Liquid Chlorine
My CH level went from 350 to 550 in a month. Fill water CH is 175, live in Kansas City and our water comes from the MO river. New pool so I’ve backwashed a few times and it’s been hot. This seem like a possible increase?

My question is, at what point do I dump water and refill? Ok to wait until it gets to 650? Looks like if I wanted to do it now I’d dump 40% of my water to get back to 400?


Free Chlorine: 6.0
Combined Chlorine: 0.0
pH: 7.5
Total Alkalinity: 70
Calcium Hardness: 550
CYA: 35
Temperature: 87°F
CSI: 0.10


Mod Squad
Gold Supporter
LifeTime Supporter
Jan 17, 2012
Evans, Georgia
If you could keep your pH on the very low end, like 7.2, it will help you avoid scale problems.

Test you fill water to see where that is now? Don't use any granular shock products which are often loaded with calcium.

When you expect a good belly washer rain, drop the pool level in advance by a couple of inches and let the rain refill. Or aim your gutters into the pool with extensions. Calcium free water! For Free!

Monitor your CSI and aim to keep it slightly negative. The older computer web version of PoolMath (found at bottom of page) makes it easy to tweak chemical levels hypothetically and see how that changes your CSI.

Maddie : :bounce:
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