Hi. Looking for some expert help...ever since pool opening this year (about 4 weeks ago now), I've been struggling with a green tint to my water. The water is perfectly clear and has no signs of algae that we can see. Have tested the water at the pool store multiple times for their advice (which as been useless so far) and even had a pool company out (they were a little baffled, they re-backwashed and actually opened the whole DE filer and cleaned it all out). The water doesn't look AWFUL, but it also isn't its normal bright blue self that we've had over the last 3 years. I thought maybe it was metals (copper or iron), but according to the most recent pool store tests (I don't know how to test for those), they said each were zero. I can't tell you how many times we've shocked the pool, and also have backwashed probably 3 times. Most recently i added 32oz of Jack's Blue magic (3 days ago) thinking that might done some metals, but that doesn't seem to be having any impact either...AARGH. I'd love any advice or suggestions. Thank you.