Low water pressue; well pump always runs

In the last few days, our water pressure has dropped dramatically. How can I diagnose whether the pump has gone bad, or if something is partially clogged?
I have a deep well with a submerged pump, and a 20 gallon bladder tank. The pump runs always, and the pressure in the tank, according to the guage, is just under 20 psi. I'm note sure what is used to be, but I think it used to turn on at 30psi, and off at 50 psi. If I open a faucet, the pressure reading drops to about 15 psi.
There is a valve in between the tank and the house. If I close that valve (shutting off the water to the house) the tank still never gets above 20 psi. With the valve still shut, if I shut off the power to the pump, the pressue slowly drops to zero. (It takes about 60 seconds.) It used to stay pressurized.
I understand that I can check the impedance of the pump, and know how to do that, but I haven't because I have no idea what it should be.
For what it's worth, our water has a lot of iron.
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Sounds like you have a large leak someplace between the tank and the shutoff valve--you can place another shutoff valve right at the tank outlet and run the system up with that valve closed to see if it then holds pressure........
If so, start looking for a wet spot, a greener than usual grassy area, etc....thats where your leak is probly at.
Oftentimes, leaks will be found at an outdoors faucet that got jarred or has settled too much over the years and broke the pipe........else maybe near where the mains passes through or under a concrete footing, tree roots, ect........
--

SVL



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Your leak could also be between the pump and the tank. I had the leak at outside standpipe happen to me this year. It was pretty much unused so I just capped off the pipe leading to it.
Harry K
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