Didn't mean to worry you. I can't find a single case of cysts in a residential pool. It's usually found in an occasional commercial pool since someone has to introduce the bug into the water in order for it to get there. It's less common today since commercial pools often supplement with ozone or UV systems. Unless you have pool parties with people who are already sick (and they'd know it with these intestinal bugs), you've got virtually zero risk for the protozoa. As for hot tub itch, most people are not susceptible/sensitive to this bacteria and it tends to flourish more in hot tubs since it particularly likes the warmer water. It takes a little less than shock levels of chlorine (0.25 ppm disinfecting chlorine) to kill this bug, but again it's very unlikely for this to be in your pool and quite frankly if it were there, it would have been there even at your higher chlorine level so don't worry about it -- if you ever shocked your pool you probably got rid of it.
Richard
