I have a Cal Spa 1993 vintage. The problem seems to be one of the air venturies does not have any effect on the jets. Open or closed is the same result. There is pleanty of water flow, (new 2.5 HP pump). I have rebuilt most of the spa and I am now getting down to the initial problem. In fact when I tested this a week ago the water level was all the way up into one of the two air venturies. Any suggestions / ideas??? The side that does work looks like the previous owner installed new check valves. Does anyone know where I can get a plumbing schematic for this Cal Spa?

OK, I guess this isn't a busy time for SPA replies. Anyway I've solved my own problem and I thought I would share in case anyone else had this issue. As mentioned eariler I received this SPA as a gift from some folks after they had three differnt spa repair men try to fix the air flow problem.
I was confident I would get this to work so I began by rebuilding the control platform that had rotted over time (whole different story). Then I thought of my old automotive carburetor experience and thought these eyeball jets are similar to a carburetor venturi, however with 10 years of 100 + degree water the seals were shot. So I replaced all the seals in the 22 eyeball jets and the low side (circulater air ventruri) worked immediately. When I posted this problem the high side (jet pump) air ventiuri's weren't working but for some strange reason it all came to life two days after running the SPA.

This is great information...I have the same problem with my floor jet/rejuvenater venturi. I've replaced most of the seals with the exception of one of the floor jets which I can't get loose, but I'm sure I'll eventually figure that out so thanks for the info!