Rising ph problem

[Guest]

Mod edit: Please start you own thread, so we can give you advice specific to your pool. Thanks, moderator linen

I wonder if someone can explain why aeration raises the pH. Is the the higher level of oxygen the water now sees? Thanks.

BTW, i also have a rising pH problem, but no aerators and no kids, so it's not clear why. I put in a gallon of 12% each day to keep the chlorine at 4-5 ppm. Doesn't bleach have a pH of about 13, so wouldn't this tend to raise the pool's pH?

 

[linen]

I wonder if someone can explain why aeration raises the pH. Is the the higher level of oxygen the water now sees? Thanks.

My basic understanding is the increased surface area caused by aeration will increase the carbon dioxide outgassing. Carbon dioxide takes the form of carbonic acid when dissolved in water, so the effect of carbon dioxide outgassing is a reduction in the amount of carbonic acid in the water and a net increase in ph.

Doesn't bleach have a pH of about 13, so wouldn't this tend to raise the pool's pH?

The net effect of adding bleach/liquid chlorine to a pool should be close to ph neutral. Yes, the addition of bleach raises the ph, but when it gets used up this is an acidic process, hence the ph neutral effects of adding it. Some cheaper bleaches and higher concentration bleaches/liquid chlorines have extra lye in them that can also raise the ph.

Post a full set of test numbers and we can help you diagnose why your ph is going up.