Well or pump

I'll try to keep it short although its been 3 days of questions. I have a 1/2 hp shallow well pump that is roughtly 12-15 yrs old, same as tank in age. I've suddening started getting alot of air, drained lines and emptied tank, found no air in tank. I put 28lbs in the tank and still seen air spurting at every faucet. Drained out lines / tank the next day and found little to no air in the tank. I assumed bladder was bad because of this and the age of the tank. Installed a new 20 gal tank and have the same problem. Pump is set at 30-50psi and I'm noticing that when its empty and turned on I can see(installed a clear flexible hose )the water without any air until it hits around 45 psi, then I see air until the pump kicks out at 50psi. From 0-45 pounds of pressue I see no air, so it looks just great until it hits around 44-45 pounds? I reduced the pressure to 45 pounds, but now it happens at around 40 lbs. Do I have a pump issue or well issue? No leaks anywhere and some good looking water flow up to a point. I'm thinking about having the well tested or even getting a new pump, but just not understanding why I get air at the top end only? Water pressure looks good to me so can't believe the well is the problem as some of myfriends tend to think.
Thanks,
Dan

This is really strange. If you have an air leak in the suction line there would be more air at lower pressures where the vacuum is greatest. The vacuum in a pump drops off with higher pressures. Is this clear pipe on the discharge or suction side of the pump?

The air has to be either coming from an air leak in the suction line, or the well is pulling down to where the bottom of the suction line is getting air or the water has gas in it.

bob...

The clear hose is on the discharge of the pump.

Good, that means less fittings in the suction line. Remember air will leak through openings water can't get through. So even if you think you have no leaks, air can still be getting in through a joint. This is why we recommend the fewest fittings possible in a suction line.

bob...

One last thing I want to mention; we've had alot of rain and around 13-15" of snow melt in the past few days. I have a pond behind my house about 200yards away, it has almost tripled in size. I have water almost everywhere around my house, but still have air and cannot believe my well is failing. If anything my screen is plugged. Did mother nature play any part in this? It all happened at once, so if anything its a major concidence that my problem happened when the world around my started flooding.

Thanks for your input,

DannyK

If your screen were plugged, it would take a long time for the pump to get up to pressure. If you have plenty of water in the home when needed, I would rule out the well or screen. You simply have an air leak somewhere.

bob...

Possibly Cavitation!

It could be that as you pump, the water level drops or the sand point is partially plugged causing the pump suction to increase in vacuum. This can cause the pump to cavitate (caused by air bubbles forming), (it sometimes sounds like a pump pumping sand).

That's especially true if the impeller is worn, and IIRC, cavitation can happen sooner with a worn off impeller.