We've had our Marquis Broadway for a year now. Started with the spa frog sanitizer system that came with spa and it seemed to work ok, though we did get cloudy water issues on an occasion that were cleared with that stuff that coagulates everything for the skimmer. Decided to switch to Nature 2 and were told that we only needed a touch of chlorine to start it up, then non chlorine shock after each use. This didn't seem right, and I found myself adding chlorine once in a while to get it clear. Just filled the tub for a third time in end of March. Double checked with pool store about nature 2 use. Was told, put in some chlorine with each use, non chlorine shock weekly. Water quality's been better, but I've developed hives! A few patches on my shin, a few on my right hand, and a rash of bumps on one forearm. I've isolated it to determine that it's the hot tub causing the hives, and each time they come back a little more widespread. In fact, I just went to the dr for a cortisone shot which helped immensely. I do have metal allergies, must wear sterling or 18k gold, so could the metals in the nature 2 be causing the problem? Really stinks that I can't go out there and enjoy the hot tub, but the hives are not worth it! Thanks for any info.