Thanks, I've read that before. I guess I'll try all that but it's at the bottom of the pool so "holding it there" is going to be kind of tough. It's also on the slant. I'm not draining the pool to get it, it doesn't bother me enough to spend 1k on water. If it's organic I guess I'll have to wait until the end of pool season, too hot right now to 'shock' the pool and wait for the chlorine to come back down, FC right now is about ~3.5.
I guess I was hoping someone had some suggestions not covered in that guide. Thanks.