I have a question about our salt water pool. Our water is very alkaline, with a PH of 11-12. It’s total hardness is zero, but KH is very high. We set up a salt water pool, 8500 gallons. I use RO water for our salt water hot tub, but that would take weeks, so I used our well water. I have added 2 gallons of Muriatic Acid, and 2 lbs of sodium bisulfate, and though i have lowered the PH to 7 several times, it keeps rebounding. The test strips are always off the scale for alkalinity, so I used my chemistry set and it indicated that the alkalinity was 1000 still. The water is clear and blue, but I’m worried that the chlorine generator will not work well, and that our filter could be damaged if the PH always climbs back. What is in our water to make the alkalinity so high? From what I read, I might have to add 20 gallons of HCL to break the buffer? Our water acts like soft water, and seems to have no minerals other than some sort of bicarbonates, as GH or total hardness is zero – I have to add calcium hardness to our water. I assumed our water has lots of Sodium Bicarbonate – but that only has a ph of 8.4, and our water is much higher than that.
With a salt cell the pH will be continually pushed up with the manufacture of the chlorine so you do need to add a reducer regularly (every couple of days). There are acid drip systems that can be added to the pool plumbing, but we find manually adding acid or pH minus helps. Products such as Pepper by API help regulate swings as well. You could try that.