Well Holding Tank Water Noise

[P.K.]

I have a 9 year old home with a 5" well. Recently I noticed that when the pump starts working, the preassure guage begins to move toward the higher reading. When it gets to about 40 lbs, I hear water running into the tank. It sounds like someone is holding a glass of water and pouring in into an empty pail. After a few seconds the noise stops, and the preassure guage jumps about 5 lbs and a few seconds later it builds up to 50 lbs, and as it shuts off I hear the water fall noise again.
Can I just put some air in the tank?
If so, how mush preassure is the right amount?
If not, should I be calling the well people to come over and replace the tank?

I assume that this noise, which just started up, is caused by something going wrong in the tank, or some type of leak, however, I hear no air leaking when near the tank.

Thanks in adavnce for your assistance

[waterdoc]

The noise you are hearing is most likely caused by a small hole in the bladder. When this happens, water will shoot up into the metal tank and cause the noise. If left alone. the water will keep building up on top of the bladder until the tank becomes completely water-logged and causes quick-cycling. You can investigate by, first, turning off the pump and draining the tank, then see if the tank completely emptied out. If there seems to be water up in the top of the tank that won't come out, the tank is bad. You can also press the air valve a little while the tank is under pressure. If the tank is completely water-logged, water may squirt out of the valve. (this is not fool-proof, just something that works most of the time) Hope this helps
Waterdoc