High return pressure to spa

Hi all,

My return pressure to my in ground pool runs about 18 psi. When I switch over to my spa it jumps up to 35 psi.
Yes the filter is clean. I even took out the DE grids and ran it with no difference in psi. The two jets that go to the spa should be a jet stream of water and they aren't. Its as if there is a restriction to the spa or something.
I have tried drawing from the pool to the spa and the pressure is still 35 psi to the spa.

I can't run my heater while in spa mode because it will cycle on and off due to insufficient water flow. Any ideas other than some thing is in the piping obstructing the flow? How do I check that?

Thanks, Mike

I'm not sure whether anyone can help you or not -- obviously, there are problems with your circulation system, but it's going to be very hard to describe what you've got adequately with words.

You might consider taking a careful, systematic, set of photos of entire piping circuit, and sending those to poolforum AT gmail DOT com. I'll upload them to the PoolForum Picasa album, and then link them in.

I will note that 18 psi is a very high starting pressure on a DE filter. I'm curious why that might be.

Ben