I have a property with a copperknight on the plumbing system. It has not been installed long enough for a true test yet. It is fairly easy to install. If you decide to get it, ask Bud if he can supply you with a variable resistor to fine tune the current to the anode. It helps to reduce the gases that the copperknight may produce and will probably lengthen the anode life. I also have another property with a phosphate feeder, its been installed 3 years and seems to be working. The chemical in the phosphate feeder also descales the inside of the piping system.