I carried over stained liner from last year.
Problem began then with huge algae problem after spring rains. Pool store noted phosphates as problem rather than algae after exhausted all to rid opaque green. Did phosphate removal per instructions from pool store including flocculent at end of process. Did Filter Aid. Also changed sand in filter! Finally pool water was clear but stain on liner was awful. Tons of money in metal removers several times. Yes, I followed directions for proper chem. levels but never got the sequestered metals out of water. Even with vac to waste many times there was and still is a dark sediment that collects in areas on bottom of pool. The water would test NO metals but there was stain on the liner. Areas where there was/is sediment, the liner isn't stained. I gave up and said I would tackle it this year.
This Year: Pool was clear with the familiar stain from last season on liner. Warmer days early and algae growth so began shocking early with pwdr shock packets. 3 per week. Cooler days followed and did not cont. shocking. Then we had rain, rain, storms, tornados and RAIN!! Yep! Green/opaque pool! Shock, Shock and then rain, rain. Two steps forward and 4 steps back. Rain tomorrow and the pool is horrid green. Now with some bubbles/little foam! ?phosphates again?
I haven't taken a water sample to the "new" pool store in town to check for phosphates.
I'm really thinking about draining it and starting over. The water will be less expensive than all the chemicals it will take to TRY and clear it up.
IF I drain it, I will still have a stained liner from last year. I presume this is copper from so much algaecide used with last years green pool. The Natural Chemistry stain remover worked on it last year. I think I used about 8 containers of that and about 6 bottles of Metal Free. The ups and downs of the water chemistry simply bound the metal then released it again to be deposited again on the liner I do believe. So much for the knowledge of the pool store employees.
Do I try to clear it up and tackle the stained liner or drain it, refill with county/public water and tackle liner stain then?
My chemistry isn't good right now but this is what it is.
I did shock with 3lbs powdered 2 days ago. Not much use with CYA at 0.
CYA - 0