Ok, after having my pool up and running for little over a week, I have crystal clear water, and am working hard at keeping my chemicals balanced. Anyway, there is ring of sludgy buildup at the water line inside my skimmer just above the basket. It is a brownish black substance, that is pretty slimy, and feels kinda like grease.

Is this normal accumulation ? Or could it be some type of algae, or something else. Also what can I use to clean it off before it builds up too much?

Advice appreciated

Bob
pool newby
E Tn.