TA is Fine, pH Won’t Come Down

[hbailly77]

Hi,

Hope I give all the pertinent information needed. We have a 390 gallon 2012 Marquis e-Series 660 Spa that we inherited with the home we just purchased. We emptied, cleaned and refilled the spa last weekend and had all the chemistry balanced within 48 hours. The kids used the spa a few times throughout the week and when I tested the water yesterday, the TA (150) Bromine and FC were right where they needed to be, but pH is at or above 8.0 (that’s as high as my test strips read). I have put numerous doses of pH Decreaser (Sodium bisfulate) in over the past 24 hours and the pH will just not go down. I shocked the spa with Spa-Shock Oxidizer (potassium peroxymonosulfate 31%) first, before starting the pH Decreaser regimine. If all other readings are fine, why can’t I get the pH to stabilize and how do I fix this?

I have been testing after the water has remained stagnant for several hours and only running the jets for 15 minutes after adding pH decreaser to circulate that through the water, so I don’t believe it’s due to aeration.

thanks!0

 

[Certified106]

Your story sounds like 4 months of my life fighting with PH until I came to this site. My recommendation is to read the stickys at the top of this forum on how to start up a chlorine hot tub and follow the portion on how to start the tub up and balance TA and PH. You also need a TF 100 test kit so you can get accurate readings and get rid of the test strips. My opinion is you are going to chase PH until you lower your TA which is addressed in the sticky. My TA is 50 and it seems to be working wonderfully.

I followed the instructions in the sticky two weeks ago and I have added nothing to my tub and my PH has been 7.5 for two weeks even with heavy use.

 

[Aqua Lab Rat]

It's pretty tough to read pH on a test strip. I can never make sense of them. Do I go by the orange-y outer part of the pad, the red-ish middle of the pad, or...? And people's ability to differentiate subtle shades of red or green varies widely.

 

[Pool_Medic]

There is no way you can go by guess strips. You need to get a proper kit that uses titration. You either overshot adding baking powder or your fill water has extremely high TA. You need to keep adding acid to get the ph down, which in return will slowly lower that TA. A spa and it’s aeration will constantly raise both so it’s almost requires a weekly dosing of acid to keep it around 7.6