Wanted to share my experience with the @ease smart chlor system.
Historically I've used bromine to sanitize my spa. During the winter my skin would get really itchy and rash in several locations. It was so bad I had to limit how much I used my spa. I did try using chlorine for a few weeks and had the same problem. In the beginning of December I switched to the Frog @Ease SmartChlor Floating Chlorine and Mineral sanitizing system. Since the switch I have not had any issues with rash and dry itchy skin. I have actually been using the spa for longer periods too knowing I won't be getting the rash.
Now, this system isn't cheap. A 4 month supply costs about $84 but it definitely has made a difference for me. @ease starter kit comes with a mineral unit that lasts 4 months and 1 smart chlor unit that they estimate lasts 3-4 weeks. My smart smart chlor unit is about empty so that timeline is about right. You can buy the smart chlor refill (3 more units) seperately from the starter kit.
I realize some of you can manage your spa with individual chemicals but I had trouble trying to maintain bromine/chlorine, pH and alkalinity previously. With the @Ease system, I shock occasionally and test the levels weekly. I don't see the fluctuations that I saw previously.