Found this forum last year but didn't transfer over to this way of treating a pool because my pool was fine. But, after the trouble we've had this year, I remembered this forum and am hoping you can help.
So, we ended up with a green mess in early May when we decided to open our pool and went to the pool store and bought back to blue. It was great because the water was clear and all the crud went to the bottom. We were vacuuming to waste and the pool was almost clean until one of our hoses pooped off and drained a third of the pool... So we had to refill which took time and the water turned green again. Anyway, we used the back to blue again and vacuuming to waste didn't go so well because it takes forever for our pool to refill with the water used to to vacuum. So, anyway, the water turns a milky green, I go to the pool store who tells me to fix my ph and add some algaecide, which I do, and there is no difference. We shock hard again and still no difference. Obviously something is going on because my pool is still a milky green despite it being two days from the hard shock and filtering non stop, and I'm tired of spending money at the pool store for no change in the water, plus it takes a half hour to get there every time I go! So, I remembered this forum and used my test kit I bought last year and here are my numbers, with the caveat that this was my first time testing so they could be a little off, but I doubt by much.
FC - 7
PH - 7.5
TA - 240
CYA - 20
I can tell already that my cya is a little low and my alkalinity is high.
Can you help me get on the right track to fixing things? We would really like to swim as the weather has gotten hot and it sucks having a pool we can't use!
My pool is a 30 foot above ground, about 20,000 gallons I think, vinyl liner with a 1.5 hp Hayworth sand filter.