MiniChlor 110 Hot Tub and Spa Saltwater System Chlorine Generator, A Natural Chlorinator Spa and Hot Tub Chlorine Generator that installs in minutes, just add salt, plug it in and drop in the SPA!! 6 Levels of Chlorine Production without buttons or knobs, no external timer needed! Self Cleaning Reverse Polarity Technology keep the titanium plates clean! Plug & Play! No Spa Modifications Required. The SPA or Hot Tub doesn't even have to be on! Works night and day so your spa will be safe to use even at night, not a solar powered supply