Pump is an F&W 1/2 HP convertible
Double-drop pipe system with set assembly and foot valve
Pipes drop to about 30 feet--well is 80 feet deep
6" diameter casing
Bladder tank @ 40 psi

Problem is that when we use water, the pressure drops dramatically when the pump kicks in. The pump runs quite a long time before the tank finally gets pressurized. The pressure does not drop after the pump stops unless we use the water. While the pump is running the water pressure is very low.

I experimented a bit by lowering the cut in/cut off adjustment, which seems to have helped shorten the time the pump runs, but the pressure isn't what it was before this business started.

According to the pressure gauge, the pressure is about 70psi when the pump is running. Shows 40 when the pump clicks off. I know the pressure gauge probably needs replacing because it will stick at about 55psi on the dial, then the needle drops to 40 when I tap it a bit.

We pulled the assembly up and checked for blockage, but it did not occur to me to check the jet itself. I'm wondering if this is a blockage problem or something else? There was a fair amount--but not a heavy amount--of black deposits on the assembly. I'm not sure if this is organic material or manganese--and we do have a lot of iron in the water.

I'm planning to haul up the assembly again on the weekend to check the jet itself--any advice as to how to clean it if that is possible?