Battle with PH and TA

[akropp]

Is it normal to have to add a gallon of MA a week just to keep ph in check? I am trying to keep my PH between 7.2 and 7.4, but every three days or so it climbs up above 7.8, prompting me to add another couple quarts of MA.

My TA is also stubbornly high — I have been unable to get it below 100, and it climbs as fast as the PH. I assume these two issues are really one and the same, but not sure if there is anything to do about it.

My current measurements:
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Chemical Addition 06-29-2019 @ 10:29 AM
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+ 93 FluidOunces of Baume31
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Test Results 06-29-2019 @ 10:21 AM
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Free Chlorine: 6.0
Combined Chlorine: 0.0
pH: 7.8
Total Alkalinity: 115
Calcium Hardness: 400
CYA: 45
Temperature: 90°F
CSI: 0.38
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Chemical Addition 06-25-2019 @ 07:24 AM
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+ 86 FluidOunces of Baume31
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Test Results 06-25-2019 @ 07:21 AM
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Free Chlorine: 3.5
Combined Chlorine: 0.0
pH: 7.8
Temperature: 87°F
CSI: 0.30

 

[Jimrahbe]

ak,

I have to ask why do you try to keep the pH at 7.2??

7.8 is just fine...

My pool will stay at 7.2 for a millisecond or less. It will often sit at 7.8 for a week or more.

Just let you pH sit at 7.8 and don't add any acid until it gets to 8.0. Then only add enough acid to drop it to 7.6.. etc..

Thanks,

Jim R.

 

[ajw22]

What is the pH and TA of your fill water?

You have an autofill on your pool?

 

[akropp]

I don’t have an auto fill, and haven’t really had to fill it much since I opened it. (This is the first year I’ve had it). I have an auto cover, so it’s always covered unless I’m using it.

Could this be because the plaster is still pretty new? (Just finished last December)

I don’t need to keep the ph at 7.2 — I’ve been targeting 7.4-7.6. I just drop it down to 7.2 so I’m not having to add acid every day. But the stranger thing is that I can’t get the TA down below 100 no matter how much acid I add.

 

[tim5055]

Could this be because the plaster is still pretty new? (Just finished last December)

Yes, the pH will rise like this for 12 - 18 months or more.

I don’t need to keep the ph at 7.2 — I’ve been targeting 7.4-7.6. I just drop it down to 7.2 so I’m not having to add acid every day. But the stranger thing is that I can’t get the TA down below 100 no matter how much acid I add.

Target 7.6 - 7.8 and add acid when it get to 8.0

The TA will start to come own, give it time.