I tred BBB in my hot tub but I'm just not having any luck. I cannot maintain a decent CL level for more than a day. It's 120 gal stand alone hot tub. The prob is that my kids and I get the "hot tub rash" easily and sure enough, got it a week ago after only 1 month with BBB. I hate to say it, but I did Baquacil for three years and never had a problem. The is just no room for error with BBB with hot water and in a tub that size I guess. You miss one day and you're screwed. I could go a week neglecting chemicals with Baquacil and not have any problems. Unfortuantely, with Baquacil the water is almost constantly clouded.