I have an in ground 25,000 gallon vynyl pool. In the beginning of the season it was clear and clean. I have a Hayward sand filter. I changed the internals of the sand filter this year and replaced the sand. After I did this the pool was great. I went on vacation and came back and the pool was turning green. I had the filter running 8 hours a day but it was very hot and I don't think I had enough chlorine. I shocked it the past 4 days and didn't get the chlorine to stay up. I added liquid chlorine yesterday and pumped it for 24 hours.
The chlorine is very high. Sorry everyone I only have test strips so I cant give you exact measurements but it has been high chlorine fr 2 days. I had the water tested twice this week and both say everything looks good.
So yesterday with the chlorine high for a day and the filter pumping for 24 hours I back washed. The clear viewer showed no green. The pool is pea soup green and after a day of filtering no green in the viewer. I opened it up and the pipe down into the sand was all connected. I suspect it is not chemicals but is the sand filter and such.
Should I continue to investigate the chemicals? Or should I take the sand filter apart? Not sure what it could be in the sand filter unit. Basic stuff. Anyone have experience with this?
Edit. It is a Hayward S244T. With new sand and new internals. Also a new pump.