Interesting. So then e.g., you could dive down to your drain and feel water circulation? I've dived down many times out of curiosity to look through the grate of my drain, wondering what its purpose is. I have my mask on and have put my hand over the grate and looked at the 4 screws beneath it that presumably keep the cover on. There is no draw from that drain. It is completely closed. That's why I assumed it's function was to drain the pool. Of course the more I think about it, that's not even logical, because if there's that kind of suction from the drain when opened, even a diver would be in peril.

So if there's circulation there, in other pools, that means the cover is off? Why doesn't it suck people to it? In this commercial kiddie pool where the girl was almost fatally injured (and whose life is forever altered) why would the drain be closed in the first place if its function is to add to the circulation of water?

Sorry for all the questions, John, but still confused.