We have a 20 X 40 IG with attatched spa. The spa has eight jets. When I run the blower 2 or 3 of the jets deliver very little air. I am assuming (probably incorrectly), that the water column in those lines is preventing the air from being pushed through. The blower is 2 hp. What is the remedy? Can I safely attach my air compressor to clear out the lines? Any help would be greatly appreciated. Thanks.