Thanks for your reply. I have a 5 drop test kit and 3 hours ago I tested 0 chlorine. I will go out tomorrow and and look for the dichlor. I expected the chlorine to get used by the algae but the loss of CYA stumped me. The water is sill quite cold, 60, but should heat up over the next few days. Also used the kit from WM to test the CYA level, only clouding the test tube water slightly. What are the ingredients of Dichlor, or does it possibly go by another name. With it heating up here I want to get this cleaned up. Thanks again!