CH question

[Fletch03]

My CH level is continuing to creep up for some reason. About 6 weeks ago it was 280 and now it is around 350. In that time period other than adding bleach, muratic acid, and the occasional baking soda, I haven't added anything else. What is causing it to rise and how high is too high before I need to replace water. Also if I continue to add water due to evaporation, shouldn't this drop CH and CYA?

Thanks for any help.

 

[Smykowski]

1. Is your pool new?

2. Have you tested your fill source?

 

[DorsalSpine]

My CH level is continuing to creep up for some reason. About 6 weeks ago it was 280 and now it is around 350. In that time period other than adding bleach, muratic acid, and the occasional baking soda, I haven't added anything else. What is causing it to rise and how high is too high before I need to replace water. Also if I continue to add water due to evaporation, shouldn't this drop CH and CYA?

Thanks for any help.

Have you tested your fill water for CH? CH and CYA only drop when you replace liquid water. Evaporation leaves CH and CYA behind in the remaining water. I don't think your CH is cause for concern but I know more about CYA than I do CH in a plaster pool. Mine is vinyl and I don't worry about CH too much.

Compare the CH level of your fill water to your pool just to see if you fill water is higher.

 

[Fletch03]

Yeah the pool is about 2 months old. I'll check fill water but when I originally filled up the pool I want to say CH was around 160 or so, so I don't think it is fill water.

 

[BoDarville]

Also if I continue to add water due to evaporation, shouldn't this drop CH and CYA?

Not necessarily. Water evaporates, but CH does not. When you refill, you are adding some additional CH even if your fill water is lower in CH than your pool water. The water again continues to evaporate, you top off, and the cycle repeats. What you are experiencing is quite common. I experience the same thing. MY CH is the same as yours and is no cause for concern (it is in the high end of the recommended range). Still worth testing the CH of your fill water to see where it is at. The CH will drop if rainfall picks up as rain water has no CH.

 

[danacc]

The new plaster may be adding CH. Use the pool calculator, and see what your CSI is. You want to keep this slightly positive to protect your new plaster while it cures. Yours isn't rising very quickly though; if your CSI is on the positive side, just make sure it stays that way.