Spa Frog Filter Mate Mineral Sanitizer

Filter sanitizer

I like to use these in my swim spa and my hot tub they seem to work as designed

hot tub use

not sure what is in it but silver is what I want. This works well in a 500 gal hot tub so i only use a tablespoon of diclor when i exit the tub. I always use these or similar

Work!

These really seems to work, but I have gotten a cople that have had loose particles floating around in the box. One of these turned my water cloudy the first day I put it in. The others have work great!