I live close to Shreveport, and was in your neck of the woods last weekend. My Cl drop has increased, too, and I very strongly suspect that the killer days we've had over the past month or so is your culprit, more than algae blooms. I agree with bumping the CYA up (I always run a high CYA pool anyway, and that's why) and seeing if that takes care of the problem. YOu're going to have to be extra vigilant about keeping the algae down during this heat, though, so shocking often is a good idea.

Janet