Low CH Causing Cloudiness???


Well-known member
May 24, 2009
I'm having a long-term problem with cloudy water, especially noticeable in the deep end (9 feet deep). It started last season and is continuing into this year. Could a low calcium hardness value be the cause?

Here's why I ask - In 1978, my first job out of college was managing a community pool. "Junior olympic" size (about 25m by 10m) with a 12-foot deep diving tank. I'm guessing about 150K gal. Gunite, plaster finish, about 20 years old. With balanced water, I slowly began to have a cloudiness problem. "Experts" suggested that low CH was causing calcium to leach out of that old plaster. Solution was to add calcium chloride (a lot!) and it worked overnight like a charm.

My current numbers:
FC - 13
CC - .5
pH - 7.7
TA - 120
CH - 120
CYA - 90 (Yeah, it's high. That's why my FC is 13.)
Temp - 80
Filter runs 24/7.

What say you experts?


Mod Squad
TFP Expert
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In The Industry
Apr 1, 2007
Sebring, Florida
High calcium levels can precipitate and cause cloudiness in your water but I cannot see how low CH (which you have) can do that.

Regardless, you need to bring your CH up anyway so it .

Nothing in your test results would indicate a cause of cloudiness with one exception.................any time a CYA value is much above 70, my antennae go up. You are doing a good job with your FC and it's obvious you understand the importance but very high CYA pools just seem to have issues.
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