salttub

Hi; We are new owners of a 8' tub, and it has the onzon system, or sea salt..granted i have been living in there, but the rash and itch is now unbearable. I'm now afraid to use my hot tub. All chemistry seems within specs, but i have no idea what to do. can someone chime in here. I used to live near the ocean, at it never bothered me.. Help!