I'm stumped. Pool has been open for a few weeks. SLAMmed the heck out of it for a week - blue, but hazy water. This then made the liner turn orange / brown (too much chlorine I guess) so I did the ascorbic acid treatment. This got rid of the brown stain. Gradually brought all the chemicals back up to where they needed to be. But water was still hazy. After that, over the course of 2 weeks I vacuumed, scrubbed the heck out of the pool. It was spotless. I cleaned the cartridge filter about 6 times. No matter what I tried I still had the haze where I couldn't really see the deep end.
All this time, the pool was uncovered day and night. Finally, I decided to put the solar cover in and not do anything about it for a few days, and then try again. Well, guess what - a day after I put the solar cover on the pool, my water turned crystal clear.
Does anyone know why this happened? I'm completely stumped.