CH Increasing


Bronze Supporter
Jul 31, 2018
Started out with 350....steadily been increasing, now approx 500....what is causing the increase? I do have a waterfall that has calcium buildup on the mortar between the boulders - from water seeping through cracks in the mortar from behind. Fill water is low CH, can’t recall, will test in the AM.


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
If your CH is increasing, it is from the fill water or you are adding calcium via chemical additions. Are you using Cal Hypo?

It is most likely your fill water. You add it due to evaporation. The Calcium stays in the pool when water evaporates.

My CH triples in about a year.


Aug 25, 2019
Clovis California
CH goes up over time. Waterfalls can cause splashing which increases evaporation along with kids cannonballing/splashing all which can cause water to splash interior edges causing more evap and calcium staining. As pool water evaporates, the calcium from that water stays in the pool. Then you add more water with calcium in it and poof CH goes up. One of the main reasons you will need to drain you pool periodically. That and sometimes super high CYA.


Bronze Supporter
Jul 31, 2018
Well that sucks....I did notice CH to start rising when it started to get hot!

Since I have a saltwater setup (+ high CH), I'll drain from the deep end, and fill from the shallow end...looks like I need to drain 25% to get back to 400 - maybe I should take it down to 350. Guess winter would be a good time to do this - can maybe use the rain to help me out with the fill.

FC - 6
pH - 8
TA - 80
CH - 525
CYA - 70
SALT - 3400
TEMP - 79
CSI - 0.14
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