Hi: I am having the same problem with Bromine...nice non-smelling green water after a few days. I am switching to ECOONE and will let you know how I make out. I also am new to the hot-tub thing...two months into it. From all I read on these forums it looks like copper in the water. I have my hottub at the cottage and use well water to fill....will perform total drain/clean of the hottub/filters etc., refill with filter on the water hose and move to ECOONE system. Later