I am in the process of creating a gray water system and need a natural, inexspensive way to neutralize the choromines present in my waste water that my municipality uses for water purification. I am already running the effulent past a gunk trap system, through a gravel bed maze, a cattail planted trough, and a peat substrate with sand blanket additional bog plant channel. I want to terminte the water into in a fishpond / tank. Therein lies my problem. Any suggestions? Thanks in advance.