Hey Stuart, thanks for the clarification. I can see that you weren't trying to cause trouble. I just interpreted it wrong. It's sometimes hard to tell by just reading words on a computer screen! The P.W.S. on the Cal Spas would pull out the ozone and chemical gasses (thanks, Lori !) hoovering in the gap between the top of the water and the bottom of the cover. This system was only on 2003 Cal Spas, however. The system did work for the most part, but if the water level in the spa got too high or some splashing occured, then a little bit of water would go down the exhaust tubes and make a "gurgling" noise that was somewhat annoying I.M.O. Needless to say, it seemed like a good idea but none of the 2004 or new 2005 Cal Spas have this system--probably because of the "gurgling" noise, but I'm not positive.
BTW, ozonators can get that moisture when someone using the spa presses their foot or toes right directly up against the ozone jet in the spa. This can back up the system and send water back to the ozone unit whether the loop is there or not, and especially if the check valve has failed.