Hi all; didn't open my pool last year because I was going to decommission it but coronavirus changed that, so it started out a swamp. It's an inground, vinyl, 18x36, about 24,000 gallons, with a cartridge filtration system.
I have the nightmare scenario where my pH is fine but TA is high (170 – 190), and although I’ve been following what I think is the right process to address that, it’s not working.
After several rounds of shock, one of oxidizing, scrubbing, and filter cleaning, the water's better though currently quite blue and cloudy - I can see to about 5 or 6 feet down. So now I've been aerating to raise pH to 7.7 or 7.8, then using sodium bisulfate (Bioguard Lo 'N Slo) to try to lower TA, adding about 1.5 pounds at a time and broadcasting it over the deep end. The first time my TA dropped to ~130, but after another round it was back to ~170, and stayed there after a third round. My chlorine is 4-5 ppm right now (coming down from a shock), and pH is about 7.6. Acid demand is very low, it only takes about 2 drops of solution to get there with the test kit. I don't know my CYA - test kit doesn't have that - so am wondering if that could affect TA? I just added about two pounds of 20 Mule Team Borax to help raise pH again so I can add more dry acid and maybe buffer it a little, but am running out of ideas. Any suggestions would be greatly appreciated.