Nature 2 spa mineral sticks are the way to go in my opinion, for hot tubs. They say they last for about 3 months each but mine are working for 4-5 months. All you need to add is a non-chorine shock to your water, which I add every time I get out of the tub. Nature 2 is a very good product. Our water is always crystal clear and zero odor.
Reviewed by: Dave from Federal Way, WA.