Light green water

[Watermom]

I'm going to let Ben address the first of your questions. But, regarding the seams of the liner ------------ my guess is that it is pollen and dirt that have settled in those lines. My liner pools have always done the very same thing. I can vacuum the pool and have it supposedly pristine. But, the vacuuming process has fine particles (dust, pollen) stirred up into the water. Then when the pump is shut off and the water gets still, that fine stuff settles back to the floor of the pool and settles in those lines. Happens over and over and has been true of every liner I have had. I cleaned my pool yesterday, but I'm pretty sure if I went out to look, I'd see those lines of debris. Not a lot you can do about that, unfortunately.