PH question

[pxranger]

Last week my PH was 8, I added the appropriate amount of MA to bring it to 7. It has been steadily climbing, today it’s 7.8. I have a poolskim that is needed to pull floating debris out and it works great. It however aerates the water which I am assuming is the cause of the quick rise in PH. We did get a lot of rain this week as well. TA is 100. Anything to be concerned about or just add MA as needed?

 

[JoyfulNoise]

With a TA of 100ppm, your equilibrium pH is approximately 8.2. That means your pool water pH will always want to increase to try to achieve equilibrium. The PoolSkim may or may not accelerate that process. If you aim for a pH of 7.6 and only lower pH once it’s above 7.8, then that should begin to reduce the acid addition frequency. The TA will decrease to a certain extent. 100ppm is unnecessarily high, 60-80ppm is a better range for keeping pH rise under control.

 

[pxranger]

With a TA of 100ppm, your equilibrium pH is approximately 8.2. That means your pool water pH will always want to increase to try to achieve equilibrium. The PoolSkim may or may not accelerate that process. If you aim for a pH of 7.6 and only lower pH once it’s above 7.8, then that should begin to reduce the acid addition frequency. The TA will decrease to a certain extent. 100ppm is unnecessarily high, 60-80ppm is a better range for keeping pH rise under control.

That’s kind of what I was hoping to hear. I’m waiting until it hits 8.0 then I’ll add MA to 7.0 and repeat until no longer necessary. The last time I did it my TA was 100. So the MA didn’t lower the TA. Any other way I should try to lower the TA?

 

[JoyfulNoise]

That’s kind of what I was hoping to hear. I’m waiting until it hits 8.0 then I’ll add MA to 7.0 and repeat until no longer necessary. The last time I did it my TA was 100. So the MA didn’t lower the TA. Any other way I should try to lower the TA?

Not quite the right strategy. pH rise is not linear. It’s faster at lower pH and slower above 7.5. So there’s no point in shooting so low unless you are trying to lower TA. If that’s the case, add enough MA to drop your TA by 10ppm then aerate vigorously to get your pH back up. But remember that you are fighting against your fill water too so you should measure the TA of that. Depending on the fill water TA, you may not want to go too low or else it’s a losing battle. Once you get a TA that makes you happy, then just aim for a pH of 7.6 and let it climb to 7.9. Then add enough acid to get back to 7.6. That should give you the lowest frequency of acid additions.