Oak tree seeds and ways to skim them.

[BigDave]

Yep. Chlorine will be used up on any organic material in the pool.

[CarlD]

I get a lot of maple "wings", pod strands from my neighbor's gazillion evergreens, and, this time of year, amazingly disgusting amounts of bird poop. I put out rubber snakes on the fence to try to discourage them. It all raises chlorine demand.