Why does my Ph continue to soar

[Madty]

I put in a gallon of acid to get my 8.2+ ph down to about 7.4- a couple of days later, right back up over 8. 26,000 gal saltwater. IG vinyl .

Chlorine stays perfect

[waterbear]

What is your TA?

[Madty]

Waterbear-- I don't know TA- I'm out of testing solution and will bring sample to pool store. Pls advise what my TA will show in relation to PH and how should I correct...how to raise , lower, etc
Thanks

[waterbear]

A high TA will make your water resistant to pH changes. TA serves as a buffer in the water to keep the pH from bouncing around but if it is too high it makes it difficult to change the pH. You need to get a set of test results to see where you are. Post them and we can take it from there.

[aylad]

If you need to raise it, use Arm & Hammer baking soda. If you need to lower it, well, that's a different animal--see the sticky at the top of the "Dealing with Alkalinity and Calcium" forum for instructions on how to lower it.

Janet

[mas985]

My guess is the SWCG. My PH always wants to be over 7.8 and continually adding acid drops my TA to about 80. I am thinking of just operating at a high PH but I am fighting high CH as well.

[waterbear]

Missed the fact that it's a salt pool.:o Yes a SWG will cause your pH to always climb. If the TA is high this will make it even harder to change the pH...post a set of test results and we can see whether it's just the acid demand created by the SWG or if high TA is compounding the problem.

[Madty]

Ok got pool numbers today-
Mineral 3000 (salt)
CYA- didn't get
Tot CL .9
Free CL .9
PH 7.8
TA 44
TOT Hardness 157 ( they said I need to add 15 lbs of balance pak- they said low hardness will eventually hurt my liner- more critical in winter they said- I bought nothing)

So is the reason my PH soars over 8 due to low TA- what to do- Borax or what?

[waterbear]

Add baking soda to bring it up and then ajdust your pH if needed after the TA is where you want it.

[Madty]

Thanks Waterbear- how much should I add? 26,000 gals TA 44

[waterbear]

According to mwsmith2's BleachCalc program you need 13 pounds to get you to 80 ppm. I would put in a 4 lb box into the skimmer and then test 24 hours later and as you get closer to your target I would add less and less and retest 24 hours later. (It take a while for the carbonate/bicarbonate buffer system to stabilze in the water. With your TA at 157 your CH is pretty low most likely. You can probably run as high as 120 ppm TA with no problems. I would shoot for around 100 to 110 ppm.

If you haven't already done so download BleachCalc....most of us on here use it!
http://home.earthlink.net/~mwsmith70/data/
then click on the link for bleachcalc262.exe to download it.

[Madty]

Waterbear-

My TA was 44 not 157- they said my hardness was 157. Does this cahnge your instructions?
Thanks

[waterbear]

I meant to say TH not TA...sorry for the typo. No, it doesn't change the instructions. You need to raise your TA. The CH is part of the TH so I was just estimaiting that your CH is pretty low.