Yeah, chlorine would be good.

They are bug poop, most likely caterpillar poop. I assume the pool is under, or very near a tree? In the skimmer net photo you can barely see a forming groove characteristic of caterpillar poop.

My biologist son happened to be home, just back from classes, so I confirmed it with him. The good news is that bug gut bacteria are not usually a big risk for people. But, again, keeping your chlorine up, is always good. And you can vacuum them to the filter which would help.

Anyhow, here are your pics: