thanks for the tip on aquabot. i will try that. so, to summarize:

we are leaning towards the assumption that this stuff is not some sort of algae, becuz if it was the high levels of cl would have taken care of the problem?

also, even if the aquabot was not picking everything up, and some of this stuff was getting by and getting filtered back into the pool, would this stuff settle back down here and there, right? but the stuff is spreadout evenly all around the surfaces. also, whatever the vacuum would miss, would the sand filter pick up. there was no visible DE in the water when i poured it in, so i guessing hte filter is working... so much to learn.. thanks