Constantly rising PH (old plaster not swg)

[Screaminz2002]

My pool PH is constantly going up on a scale of .2 a day. Started with very high alkalinity 240 on a fresh pool which was normal. Lowered the alkalinity to 110 over two weeks by aeration and adding acid. This is when the PH kept going up requiring acid which dropped my alkalinity down to the 60 range. So now its a constant battle of adding baking soda and acid to keep it right. Also note it has been 95° plus here most days. Average for last month looks like this:
FC 3.1
ph 7.6
ta 61
hardness 400
cya 30

the CYA really dropped as well. Prior month was 45 ish. Guessing evaporation and rain? I am going to add an offline feeder this weekend.
Re plaster is around 14 years old and it is not swg. I don't see any visual leaks at all. Pump and filter system was replaced last year as it was basically the original stuff from the 80's. Could the new filter be causing this? I dont see any visual leaks and there are no bubbles in the jets. We did have some scaling over the winter. I drained it and pressure washed the tile. as it had been quite a few years since it had a good cleaning. We decided against an acid bath since the plaster is getting up there in years. I am at a loss at this point. I have never had this issue before. Hopefully someone has an idea.

 

[mknauss]

Can you let us know how you obtained those test results?

 

[Screaminz2002]

k2006c

 

[Screaminz2002]

Bump, still happening

 

[mknauss]

k2006c

Great. The test results you showed above are not all possible using that kit.

Let the pH rise to 8. Lower to 7.6 or 7.8 at most.

Be sure all forms of additional aeration are stopped or minimized.

 

[Screaminz2002]

Great. The test results you showed above are not all possible using that kit.

Let the pH rise to 8. Lower to 7.6 or 7.8 at most.

Be sure all forms of additional aeration are stopped or minimized.

Please explain how the tests are not possible.

Been doing exactly this for about 3 weeks now. Im wondering if the plaster failing would trigger this. It is at the end of the life cycle and I am starting to see very thin spots around the top. Already have some quotes to get it done. Im pretty much at a total loss on this as it doesnt make sense.

 

[mknauss]

A FC of 3.1 and TA of 61 is not possible using the expected test procedure for the K 2006.

 

[Screaminz2002]

Those were averages for the month, not a one time sample.

 

[PoolNewb2020]

In order for the experts to have the best shot at helping you out, you need to provide the latest test results, not averages over the last month.

 

[Screaminz2002]

Kind of starting to feel like I need 10ft of fuel line from autozone lol.
Latest test:
FC 7.5
CC 0.5
PH 7.4
TA 90
CH 460
CYA 30

Just added liquid 32oz of liquid conditioner and the PH was a oops from the wife. She added a bit more acid then she needed to.

 

[mknauss]

Those look fine. Let pH rise to 8 and when it goes above that lower to 7.6 - 7.8.

Minimize all sources of aeration.

 

[JJ_Tex]

And did I read that right that you lowered your TA to the 60's, but then added baking soda to get it to the 90's? If so, I would have left it in the 60's as that is still within range and will help slow your pH from rising.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

 

[Screaminz2002]

So any idea of a source for the rising PH? This isnt normal and there is something else causing this.

 

[Screaminz2002]

The problem is since hitting my normal number of 90-100TA and 7.6-7.8PH the PH is non stop climbing at a rate of almost .2 per day. So every other day I am adding acid to drop it from 8. This is lowering my TA and at 60 I have to bump up back up to 90-100 range. This is a lot of acid and a lot of baking soda. Its getting to the point that I am going to aerate the thing and stock it with fish.

 

[Screaminz2002]

And did I read that right that you lowered your TA to the 60's, but then added baking soda to get it to the 90's? If so, I would have left it in the 60's as that is still within range and will help slow your pH from rising.

What Are My Ideal Pool Levels?

Use our tool to find ideal chemical levels for any swimming pool. Check TFP recommended levels on pH, free chlorine, cyanuric acid, and more.

www.troublefreepool.com

The problem is the rising PH. I would be fine at 60 but I have to constantly add acid to combat the PH which keeps dropping the TA.

 

[JJ_Tex]

So stop adding the baking soda and leave your TA in the 60's. I would kill for a TA in the 60's (Edit - We posted at the same time). A lower TA should help help keep the pH from rising, but its still going to rise.

Also, do you have an autofill? If so, you could have a leak as I bet your tap water has a pH in the 8's.

 

[Screaminz2002]

No auto fill. In fact I added water Friday for the first time since I filled it. I cant leave the TA at 60 if I am adding 1/4gal of acid every other day. 3 doses drops the TA 10.

 

[mknauss]

Let your pH rise to 8 and do not lower it any further than 7.6 to 7.8. It should stabilize. Resist adding baking soda until your TA tests below 50.

Do you have any sources of aeration?

 

[Screaminz2002]

No aeration. How high do I raise the TA after it falls below 50?

 

[JJ_Tex]

I would at least try only raising it to 60 if you go below 50. Obviously if you have to constantly add baking soda, thats a PITA and you could go higher.

I'm sure others can speak to the science behind it, but I know when my TA was 60 I hardly ever had to add acid to keep my pH in the 7's. Now that I have crept up to a TA of 100, I have to regularly add acid. Once I get a lull in work, I plan on aerating and adding acid to lower my TA back to 60.