Struggling to keep pH down

[atxjhawk]

Hi all. I seem to be frequently adding acid to keep pH in a reasonable range. It will rise to 8.2 within a few days of bringing it down to 7.5-7.8.

This morning's test results after adding 18 oz of acid yesterday afternoon:
FC 7.0
CC 0
pH 7.5
TA 70
CH 400
CYA 60

The table below shows abbreviated test results and acid added as a result. I use PoolMath to determine how much acid to add for a target of 7.5.

Date	TA	pH	Muriatic Acid Oz
09/30/2016	80	8	18
10/1/2016	100	7.8	11
10/04/2016	80	8.2	18
10/05/2016	80	7.8	9
10/08/2016	80	8	18
10/11/2016	90	7.8	9
10/14/2016	90	8.2	18

I mostly have the water fountain turned-off to keep aeration from increasing the pH.

Is this just normal for my pool or is something else affecting pH?

Thanks,
Steve

 

[Jimrahbe]

Steve,

If this is a new pool or has new plaster, that will cause pH to rise. Your waterfall (aeration) will also cause pH to rise.

I suggest you try this...

Measure and record your TA. Use pool math and drop your pH to 7.0 and immediately turn on your waterfall. Wait three or four hours and measure and record TA again. Measure pH and then add acid to drop it to 7.0 again. Wait three or four hours and measure TA and pH again. Do this same process over and over, until your TA drops to 60 and then let the waterfall run until your pH gets back up to 7.5 or so.

Thanks,

Jim R.

 

[atxjhawk]

Thank you for the recommendation, Jim.

The pool is about six years old.

Steve

 

[duraleigh]

This is the process that Steve describes.....

Pool School - Lower Total Alkalinity