I have a 6 year old Coast Spa with No blower with only air comeing out of the jets on one side of the spa. When I look underneath the inside where the air control valves are located, I can see the clear tubing where the air is sucked through. On the side of the tub with hardly any air I can see some water moving around in the tubing. Is there any way to clear the water from these lines, and would that be the problem? How would the water get in the air lines? Any help would be appreciated.
Thanks

http://spasupport.com/airlocks/jetlock1.gif

That diagram shows how an airlock can occur between two jets because of the design and rise of the plumbing hose. (This particular diagram actually shows how an airlock between two jets will cause the end jet to have a REVERSE water flow because of it).

Now in your case you've got an independent air line attached to the affected jets that aren't daisy chained with the rest of them, however the affect is the same. If there's an airlock between the jets themselves, then there will be no water pressure to create the venturi effect that pulls the air into the tub, which removes the water.

All that said, remember that when your jets are turned off, the water will rise up to the level of the tub IN THE AIR LINES because it's normal.

So, since you don't have water pressure in those jets, the water is in the air line.

The only way I've ever found to be able to remove this kind of inter-jet airlock in the past (this problem is more prevalent on a few older CalSpas) is to close down the jets in the chain prior to the airlocked ones. This will force the water into the air locked cavity pushing the air out.

Your mileage will definitely vary.