Pool has gone from Acidic to Basic - why?

[jgold723]

My pool used to run consistently on the acidic end of the pH scale -- 7.2 to 7.4. I was using the trichlor hockey pucks for chlorine.

I switched to liquid chlorine a little over a year ago to reduce the CYA levels (it worked).

However, now the pool runs consistently basic, around 7.8. I periodically add muriatic acid to bring that down, but it keeps going up.

Nothing else in my pool care methods have changed. Is it the chlorine? Is there a better way to balance the pH than what I'm doing?

 

[mknauss]

The trichlor hockey pucks are very acidic. So they were adding acid to your water constantly.

Sounds like your pH is pretty stable with only occasional additions of acid. All is good.

 

[SunnyP2000]

My pool used to run consistently on the acidic end of the pH scale -- 7.2 to 7.4. I was using the trichlor hockey pucks for chlorine.

I switched to liquid chlorine a little over a year ago to reduce the CYA levels (it worked).

However, now the pool runs consistently basic, around 7.8. I periodically add muriatic acid to bring that down, but it keeps going up.

Nothing else in my pool care methods have changed. Is it the chlorine? Is there a better way to balance the pH than what I'm doing?

i dont have the answer but following. my PH is always around 7.8 and just wondering why? just like you i would add little acid to bring it down to 7.5 but it goes right up. btw i dont use pucks.

 

[JoyfulNoise]

Any body of water with carbonate alkalinity in it (which is pretty much all of the water on the surface of the Earth) will always have rising pH. Dissolved carbonates cause pH rise through the process of CO2 exchange with the atmosphere (known as CO2 outgassing). Your water was only “acidic” because the trichlor pucks were constantly adding acid to the pool. Liquid chlorine is effectively pH neutral when added to a pool so the release of CO2 from the water is what is driving your pH up.

 

[woodyp]

7.8 is just fine btw.and if you lower it...lower it all the way down to the bottom of our recommendations.

 

[jgold723]

Thank you all -- I appreciate the insight and advice, as always!

 

[cledee]

Pools with SWG probably have more issues with rising PH than pools with non SWG. But the main key with rising PH is alkalinity. So if you keep your alkalinity within the recommended ranges your PH shouldn't rise as much. So far this year my PH has stayed between 7.5-7.6, compared to last year when I had to constantly add acid to drop the PH from 8.0 to 7.2. The main difference is last year my alkalinity was 115 to start, compared to this year my alkalinity was at 50 to start.