I have been out of the tub scene for a while, but recently picked up a Freeflow Passport spa, and have been happy with it so far. It's a 200 Premier Model, and according to the manual which is otherwise useless, the tub has an Ozone Jet that comes on periodically to clean the tub. The manual does not say where it is, or anything like that. Also, on my control box, there is an ozone label, with a separate wiring coming from it, but I have no idea where it leads. Is this "ozone" just a marketing gimmick, or is there something actually there that does some sort of cleaning? Thank you like always everyone.