Thanks again. I've had a couple of other people look at it. They think the line from the skimmer to the pump is either cracked or blocked. This is an older pool and currently the skimmer is the only source for the pump to draw water from. This is also true for vacuuming. I've dealt with blockages before, but this one (if that is what this is) is different due t the amount of water that is reaching the pump. As stated the cleanout pot is never empty and circulating water is always present...it's just that circulation and water level is diminished.

Interesting note. When I place my head to the ground about the area that a PVC elbow joint should be I can hear a lot of swishing and bubbling noises. Closer to the skimmer I hear a gurgle from time to time. We'll see. A pool guy is coming out tomorrow to pressure test the line and then blow it out if able. Trying to locate a plumber that can scope the line also. to see what we're dealing with.