Pressure problems

[Sumo1]

Thanks for the response. I've lived here for 4 years. I believe it was built in 1985. I neglected to mention that there is a Tropic Air 1hp pump that blows air through the spa jets. I have 2 skimmers, one about 20' from the pump and the other at the far end of the pool. The far skimmer doesn't draw very well so I've had it plugged all summer. I bought new DE grids 2-2 1/2 years ago. I can only remember seeing pressure as low as 12-13 maybe once or twice since I've been at this. Since I've got all these various pumps, perhaps I could downsize the main to 3/4 or so?????? I usually run the system about 10hrs a day. I would love to reduce my pool related power consumption. There's also a pool furnace but we haven't used it in 2 years. Ideas??