Quote Originally Posted by jwilliams View Post
Pitting goes around entire perimeter of pool. 30k gal kidney shape. Filter runs 8 -10 hrs / day.
Waterbear posted while your post was in moderation, where he couldn't see it. However, it's a worthwhile point: if you use floaters AND don't run your pump continuously, that might explain why the pitting is localized to the pool perimeter, rather than being uniform.