Ok - I'm been reading info on your site to help with my recurrent green algae. I've come to the conclusion (for starters) that my CYA level continues to be too high because I am using trichlor tablets and shock. Do I understand correctly that I need to replace these chemcials with bleach? Does the pool calculator tell me how much to add and do I just pour it into the pool directly? Should I start here before making any other adjustments? Also, did I read that the only way to reduce CYA levels is to drain water?