Soda Ash Clouding Water -- Calcium Saturation at 130ppm?

[Shocking]

Make-up water has low CH here (western NC) and I've been struggling to get CH up to levels appropriate for a plaster pool. Fighting against a pool leak requiring a lot of water addition every day. But I've finally reached CH~130ppm.

FC ~4ppm
CC ~0ppm
pH ~7.4
TA ~80ppm
CH ~130ppm
CYA ~20-30ppm
Temp 85F

I would keep adding calcium chloride, targeting a higher CH, but I've started encountering temporary clouding of water every time I add soda ash for minor pH increases (~0.1) . No big deal except this is a community pool where folks get upset if the water isn't crystal clear at all times.

I've tried slowing the soda ash addition way down, but it really is sensitive and clouds wherever I add it. You can see it creeping across the pool!

I tried aiming inlets up to aerate, but that doesn't seem to keep pace with the downward pH list due to CYA and make-up water.

Have I reached calcium saturation? I thought that wouldn't happen until CH~200ppm. And if I do need to keep adding calcium chloride. Any ideas on preventing the soda ash clouding?

 

[duraleigh]

CH of 130 is certainly not saturation by any stretch.

Why don't you switch to 20 Mule Team Borax to raise your pH?

 

[chem geek]

Your saturation index is at -0.5, but when you add soda ash that raises both pH and TA locally until it is diluted, it can cause temporary cloudiness. As Dave points out, you can use 20 Mule Team Borax to raise the pH and it will only raise the TA half as much and will probably not cloud up. Or you can add whatever product you use at night when presumably the pool is not in use (keep the pump running for a few hours to disperse the chemical).

 

[Shocking]

Extremely practical, both short and long term. I'll use up existing soda ash supplies by applying in the evening, then switch to borax. Or at least I'll be much more aware now that borax is an important option and why. A boost to TA is often a good thing here, where make-up water drives TA down. But I like the idea of using borax to focus on pH when that alone is the issue. Also glad to begin learning about borates, which look like a helpful borax bonus.

Thanks again!