I have suffered for years with Degenerative Disc Disease. Been to Chiropractors, Pain Management Doctors and Acupuncturists with little relief. We got our Glow exactly a year ago and with daily use, my back pain is almost non-existent. There is no doubt in my mind the hot tub has improved my condition. I couldn’t be happier with our Glow. The only reason I didn’t give it five stars is there is a learning curve on the Ace System but I think I have it figured out now. I take a water sample to my neighborhood pool supply store for analysis every couple of weeks. I have a hard time reading the test strips and this takes all the guess work out of it. I also increased the output level which was not high enough to keep up with my use.