My liner is just two years old. We used the city hydrant to fill it. Last year, I just thought the edges where the sun hit it were causing fading. This year the white film is all over. After some reading....I realize I've been doing a few things wrong. I always kept my I chlorine high...like way too high (~20ppm). Not a wonder I needed to add PH increaser all the time. I also tend to keep it around 90 degrees....we only get about 3-4 months to use it and like to swim at night. So anyway, I did the Vitamin C test and the stains faded. It took 6 lbs of Sodium Thiosulfate to bring the chlorine down and I used 1000 Vitamin C tablets. The local store sold me Spot Clear to remove iron. I used 4 pounds for a 30,000 gal pool. Less than half an hour later.....my pool is green! And I had the filter running, not on recirculate. Oh, and I vacuumed the bottom too......Now what?
Do I need to change the filter sand?
Do I need a sequester agent?
Steps to balance?
30,000 IG pool, vinyl liner
18x36 kidney shape (22 at widest)
Sand filter, city water