Correcting Muriatic Acid Dump

Baylor840

Member
Jun 1, 2020
6
Burleson, Texas
We have a month-old, 23k gal., IG plaster pool (pebble tec). There had been some light yellow-ish staining in the bottom of my 7.5 ft deep end around the main drains. PB and plaster sub were of the opinion that it was dirt that settled on the fresh plaster during our fill. I came home from work today to see the plaster sub applying Muriatic Acid locally to the staining to try and get it up. From what I can tell he used about 2 gallons of 20 baume. It appears to have helped somewhat with the staining, but, obviously, my pool's PH is now very low. Per poolmath, I need to add a bunch of Borax to get the PH back up (13+ pounds, and likely more as I believe the PH is below the 6.8 registered by the test).

My question is, is there any harm in drastically raising the PH once it has been drastically dropped in such a short period of time? I had planned to add about half of the recommended amount of Borax tonight, but the idea of wild PH swings gave me pause. Any harm in starting to get PH back in balance quickly?

Thanks for any help!
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,283
Laughlin, NV
They should be managing that. Check with them. They may want it low to remove the stain. Be sure you are NOT running your pump. That low pH water will destroy your heater.
 

Baylor840

Member
Jun 1, 2020
6
Burleson, Texas
Thanks for the quick replies...talked to PB - he was not aware of the acid addition and told me to "dump in a box of baking soda, should take care of it." I went ahead and added the Borax instead. Unfortunately, the plaster guy had turned the pump on when he left, so hopefully not too much damage was done to my heater.

The addition of the Borax (3 x 4lb boxes) got me to a PH of 7.2 and a TA of 50. I have my bubblers and sheers running to try and get some additional PH boost from the aeration. I am hesitant to add any additional Borax right now, as we are in for a bit of rain today. See any issue with this approach?
 
Last edited:

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,283
Laughlin, NV
I would not add any more borax. If TA tests at 50 again I would suggest adding some baking soda to get it to 70 ppm. Then monitor and manage as normal.
 
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