Here are 2 pictures of the problem. These patches are more towards the outer edge of the pool. 24 ft pool, and the problem is fairly well confined to the outer 6 or 7 feet. Approx 6 to 7 feet from the center out has no noticeable problem (yet) As the cl level is increased, the darkness of the patches starts to go away.
I am now working on getting the cl to the range of 15ppm (as suggested here). Should I work on lowering the PH from the 7.9 now, or what until I get the CL level up.

Thanks

David