TA & PH rise


May 9, 2019
Houston TX
First, thanks for all the help while I was getting my pool back under control. Life is good and the water is clear. Looking for some guidance or at least a "hey you're headed in the right direction"

I took over pool management in the middle of May. Getting CYA under control required a partial drain/refill and we have high TA in our fill water, so my pool started mid May @ ~160 for TA. By the end of May, I'd gotten that number down to ~80 or so. Since EOM May, the TA has slowly trended downwards to 60. The big rain we got last week finally got the number down to 40. I dumped in the requisite box (55 oz) of washing soda, managed the PH rise with 48 oz of acid over the course of the day and now find myself here:

Build Type: Plaster

Volume: 19000 gallons


Latest Test Result Summary:

FC: 5.0 (11 hours ago)

CC: 0.0 (11 hours ago)

pH: 7.7 (11 hours ago)

TA: 60 (2 days ago)

CH: 280 (3 days ago)

CYA: 40 (3 days ago)

TEMPERATURE: 84° (11 hours ago)

CSI: -0.12 (11 hours ago)

What I find is that every 2-4 days, I'll need to add 24 oz of Muriatic acid to bring pH from 7.9/8 to 7.3. I assume I could do daily acid treatments in smaller doses to regulate pH more closely, but I prefer to handle acid less if I can.

My understanding of the role of TA is rudimentary, but what I read is that TA acts as a sort of buffer for acid demand. I don't notice any swings up or down with pH in my pool - it just seems to rise steadily .2 per day until I squash it down with acid. Is this normal? Should I futz with TA in such a way that I only have to add acid every 5-7 days instead of every 2-3 like now? I hear borates can help? Give me some ideas plz


Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
You're going through a yo-yo phase trying to adjust too much. Some pools find a pH of 7.7-7.8 is better. Trying to knock the pH down to 7.3 can be fruitless sometimes. It will only remain low for a short time, and the acid dosage also drives the TA too low over time. Your CSI is in good shape with those numbers above, so I'd just leave it. When the pH does creep over 7.8, use just enough acid to lower it to about 7.7. I also would not let the TA drop below 50 in the future.

Now in 2-3 months when our water temps drop a lot more, you can let the TA and pH remain a little more elevated because the colder water will pull the CSI down. Hope that helps.
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