PH Trouble


New member
Jul 10, 2012
Having an issue with th PH in my hot tub. I recently drained and filled the tub with fresh water and Bromine salt. Initially my TA was 0, and PH was 7.3 so we added baking soda to raise the TA. TA went to 120 and the PH to 8. I added 1 oz of muratic acid which lowered PH to 7.5 for a day, now my PH is back at 7.9. Tested TA again and it's 50 PH is again 8. This cycle is recurring and and with a TA at 50 i now need to add baking soda again. Just looking for thoughts on why my PH keeps driving up so fast. I know it will gradually raise, but within 12 hours is just ridiculous.

450 gallon bromine tub

Right now

Br is 10
TA is 50
PH is 8
CH is 200


Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
Aug 10, 2012
FL panhandle
Ok, things are a little off here. It isn't possible for TA to be 0 and pH to be above 5.0. But, for a hot tub you want the TA to be 50 and the pH to be 7.8. Ypu can add 50 ppm of borates to help stabilize the pH.

There is more info about managing TA and pH here, How do I use Chlorine in my Spa (or pool)?

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