Roger, Ardie's husband here and this is the problem. Any ideas?? Using an above ground deep well pump, Red Lion RJC series, Â½ horse. The run from the house to the well is about 30 â 40 feet of galvanized pipe, and then down I would guess, 40 â 50 feet. Not really sure of the well depth. A 20 gal. Captive air tank with a neoprene bladder is piped next to the pump. The pump has a screw type control valve to control the output of the pump. The pump was maintaining a maximum pressure of about 40 lb., but the most I am able to obtain is 30 lb. now. I have replaced the pump seal since I took the pump apart to inspect the impeller. I did not replace the plastic diffuser in the pump, as it appeared to be ok. The impeller appeared ok also. I have also changed the air pressure on the captive tank, which helped a little volume wise, but not pressure wise. Do I assume the water level is lower, the jet in the well is going bad, or could it be the diffuser in the pump, or simply a rotted pipe that might be drawing air, or everything at once?