PH issues

[Screaminz2002]

Fighting high TA. Started at 240 and have brought it down to 140 by aerating and lowering PH daily.
Yesterday 8am PH 7.7. Added 28oz of 31.45 acid.
At 1130 it was down to 7.4. Added 12oz.
At 6pm it was at 7.5. Nothing added and stopped aerating overnight.
This morning at 7:30 it was 7.8. Added 37oz and started aerating.
At 10:30 7.7. Added 18oz as to not overdue it and stopped aerating.
At 1pm it had climbed to 8. Added 64oz .
This is the first time I have seen the PH rise like this. Did have some rain last night but nothing over the top. I can usually see the drops in PH around 2 hours. Could it be a bad bottle of acid? Maybe something wrong with the regent? I usually don't add have to add this much acid. Usually one shot in the morning and it's good for 24. This is the first time it didnt drop.
Pool is 16k gallon. Pump turnover is 4 hours and has been running 16 hours a day. Chlorine has been fine. Hardness is a little low at 240. Raising it once the TA is a bit lower. CYA is 45 although this is hard to measure with the little dot.. Water temp has been 88-90°.

 

[Texas Splash]

Your plaster isn't new is it? I'm actually surprised to see y our TA so high to begin with for our area. Have you tested your tap water? I'm sure that's why the pH is flying up so fast. In any case, let the pH get all the way to 7.8 before hitting ti with enough acid to lower it to 7.0-7.2. You need that full range of motion to really impact the TA. That should start to put a dent in it. If the reagent isn't from this season, I'd get a new bottle to be safe. My water temp just crossed over 90 yesterday. Starting to get warm around here.

 

[Screaminz2002]

Re-plaster was in 06. TA has always been 200+ on a fresh fill for the last 18 years. This process is something I have to go through anytime I drain the pool. I'm getting a good TA drop of around 10 per day but have never seen the PH fail to drop like this. The wife has been testing and I am wondering if she had some residual chlorine test in the beaker when she tested it. In 1.5 hours the PH dropped to 7 with the last 64 ounce dose. It going to dip under 7 but the aerators should bring it back up pretty quick. Probably just let them run all night. That rules out a bad bottle of acid and leaves wife error lol.
Yeah SA got hot fast. I put the solar cover on for two days after my slam and it hit 90. Been off ever since and hasnt dropped below 86 even aerating.

 

[Texas Splash]

leaves wife error lol.

I vote to blame the wife as well. I get blamed for too much already.