white residue or scale in fiberglass pool

[karrde97]

I just noticed the same problem for my above ground pool. The water looks lime green yet everything tests perfect. When I stuck my hand in and rubbed the side, it was very course and whitish. I ran a scrub brush over it and it barely made an impact. What is it and how do I fix it?

[kelemvor]

You'd probably be better served by starting a new thread and including a full set of test results in your post as poolhouse did above. Photos can be helpful as well when you're talking about mean green.