Pool ph

[Aimbdd]

So, we remodeled and plastered our pool about two years ago, and are having some pretty extreme ph drift this year, I was wondering if anyone had any advice? I basically have to add 300ml of acid daily to keep it under 7.8, It will stay at 7.8 for a day or two if I don’t add any, but will start to climb. I use liquid bleach to chlorinate.

Fc: 4
Tc:0
Ph:7.8
Ta: 55
Ch:390
Cya:35
Temp :88
24k kidney shaped concrete pool, white plaster finish

 

[the_sphynx]

I don't have any surefire ideas on this one but I had some pretty wild pH/Acid demands earlier this year I solved by lowering my high TA. I was putting in a gallon over a two week period which for me is a lot and then I realized my TA was too high (like 80). I have a salt pool so I put a ton of MA in and then aerated the pool. This brings the TA down then the aeration brings the pH up. I brought mine down to about 60.

You need the opposite to happen as 55 TA seems a little low to me. My TA and pool seem much happier at about 60-70. My demand for acid is way less now. Like I only put in 12-15 ounces every 3-4 days or so. When I add the acid the pH shows it in the 7.6-7.8-ish range.

I'd also say that, at least for me/my pool, it just naturally sits at a higher pH. For me, I am not targeting a number like 7.5. My pool seems to be perfectly fine within a range of 7.7-7.9 pH. I don't notice anything negative keeping mine on the higher side of the spectrum. When I first got the pool handed over to me I was trying to keep it at 7.2-7.4 and that was just not realistic and over time I learned the unique needs/desire of my pool. HTH

 

[Texas Splash]

You might double-check your TA or the math result. TA drops are multiples by 10, so your results should be 50, 60, 70, etc. Your plaster should be fully cured by now so that's not a contributor to the pH rising. Sometimes it's fill water added. Other times it's lots of aeration from swimming, and of course a high TA will let the pH rise quickly.

 

[Aimbdd]

Yeah, it was 60 at beginning of week but with ma additions around 55.

 

[Texas Splash]

Some pools simply find their pH stabilizes better in the upper 7s. Your TA is about as low as you want it to go, so not much else to do there. If there are no aeration sources, then your pool may simply need a small amount of acid every 2-3 days or so to keep it under 8.0. Mine does.