I have an IG, fiberglass, sand filter, 15k gallon, 3/4 horse pump (that runs 24/7),cloudy water filled hole in the back yard. We also use a Dolphin 4 pool cleaner daily. This is the third year we've owned it and the third year we have had the same problem. This year I have invested in a Leslie's Poolcare DPD Test Kit and tested the water morning and night. My results:
TA- 220 ppm-ya I know
I've gone through 7 gallons Muriatic Acid, with no results.