Balancing pH

[Poolboynewbie]

I am having a hard time keeping my pH down. It gravitates to about 8.2 all the time and I have to put quarter gallon of muriatic acid a week to get it back down to 7.6 and by week end Im back to 8.2. I am not running any spill overs or anything either. I tried to move the TA to 70 to see if it makes a difference but its the same and the amount of MA Im putting in, brings TA back to 40.

My pool specs are below

Pool size: 18,000 gallons
Type: Pebbletec
SWG

Cya:70
TA:40
Salt:3100
Calcium Hardness:400
FC:4
Borates:40

Id appreciate any advice

 

[Bperry]

I am having a hard time keeping my pH down. It gravitates to about 8.2 all the time and I have to put quarter gallon of muriatic acid a week to get it back down to 7.6 and by week end Im back to 8.2. I am not running any spill overs or anything either. I tried to move the TA to 70 to see if it makes a difference but its the same and the amount of MA Im putting in, brings TA back to 40.

My pool specs are below

Pool size: 18,000 gallons
Type: Pebbletec
SWG

Cya:70
TA:40
Salt:3100
Calcium Hardness:400
FC:4
Borates:40

Id appreciate any advice

Are you sure its getting to 8.2 or is it just off the scalenof whatever kit youre using? Generally we advise people to let it get to 7.8 and it likely will stay there much longer before rising. Pushing it to 7.6 just makes it want to rise faster.

Also if you have water features that aerate the water, that raises the pH.

 

[Rancho Cost-a-Lotta]

How are you chlorinating the pool? What is the TA and pH of your fill water? How are you testing your water? When doing the TA test, are you continuing to add drops until there is no color change?

 

[Rancho Cost-a-Lotta]

I saw your original post you're using a SWG. You can disregard that question.

 

[Meon2wheels]

Can't help you, but since I'm having the same issue with drifting up PH, I'll post here too.

Pool Specifics:
Age: 8 yrs
Volume: 16,500 gal
Type: Liner
Patio: Concrete
Additional features: None (no, falls, spa, fountains, etc)
Environment: Partly shaded by maple trees (see profile photo)
Filter type: Sand
Filter operation: 24hrs/day, 1HP pump
Chlorinator: manual liquid (10%)
Usage: Light, 2 people ~ 2hrs/day
Water quality: crystal clear since May

Chemistry:
Alkalinity: 100ppm stable
Stabilizer: 40ppm stable
Total Chlorine: ~2ppm variable
Combined Chlorine: 0 stable
PH: 7.5, raises about 0.1/day

Maintenance:
Robot vacuum every day (3 hrs)
Skimmed daily
Brushed weekly
Filter delta P: 10.5 psi. Backflow about 1/mo at +10psi delta
Chlorine: ~45 oz 10% solution added every evening
Water source: City, PH 7.4
Water tested using TFP test kit, and 5 drop PH test.

I also have to add ~1.5 lbs PH down about every 4-5 days. Any guidance would be appreciated.

Jim

 

[pjt]

How are you testing?

I tried to move the TA to 70 to see if it makes a difference but its the same and the amount of MA Im putting in, brings TA back to 40.

Once your TA is 50-70, you need to be judicious with MA dosing. Only add enough to get your pH into the high 7s. TA down to 50 is perfectly fine. pH rise will be minimal with TA ~60.

Are you adding baking soda or any other chemicals?

You need more FC. Target ~7.