High Calcium

[dj_pool]

Greetings,

It's been 6 years since I last drained my pool and since I was having my tile cleaned and replacing my filters, it seemed like a good time to do a drain/fill. My question is about calcium levels. My calcium levels have been way high for several years. I know when I last drained/filled, initially the calcium was too low and I added some to get closer to a normal amount. But over time, the calcium just kept getting higher. I am using liquid chlorine. Maybe there isn't anything I can do about that but I don't know if the calcium builds up over time due to evaporation or leaching from the pool shell? The pool is refilling as we speak and I'm not sure if I should add any calcium on "startup" with fresh water.

Thanks!

 

[JoyfulNoise]

What is your fill water CH, TA and pH? Measure it with your test kit. Typically people in arid climates should never add calcium to their pools, it’s not necessary and will build up naturally due to evaporation and refill.

 

[ajw22]

Post pH, TA, and CH of the fill water going into your pool.

Calcium accumulates in the pool from evaporation and the CH added by your fill water.

 

[dj_pool]

Thank you for the replies, I can test the fill water and post.

 

[dj_pool]

I just tested my fill water:

pH = 7.4
TA = 90
CH = 110

Sounds like there is no need to bring up the calcium levels.

 

[ajw22]

We like CH in a plaster pool to be at least 250ppm.

CH of 100ppm is not very high for fill water.

What was your CH level in your pool before you drained it that you thought was high?

 

[dj_pool]

If I'm remembering correctly, the CH previously was close to 1000ppm.
If the CH is only at 100ppm after the fill, should I raise it to the 250ppm level?

 

[JoyfulNoise]

Do not raise your CH using calcium chloride (calcium hardness increaser). That fill water isn’t terrible and you live in a part of the country with naturally hard water and fast evaporation rates (unless you are covering your pool).

If you manually chlorinate your pool, you are a perfect candidate for using calcium hypochlorite as your chlorine source. Every 10ppm of FC added using cal hypo raises CH by 6ppm. Once you get your CH to 250ppm, you can simply switch to liquid chlorine. Cal hypo will raise pH due to its caustic nature so you’ll want to adjust your pH down to 7.2-7.4 before adding the cal hypo.

 

[dj_pool]

Thank you