Ok, here it goes.
Came home, no water. Replaced well pump ourselves. Voilà, we have water. The pressure was pretty low though. The water pressure has gotten increasingly lower as time goes on. It just took me an hour to fill my small bath tub up halfway. It literally trickles. There is normal pressure for about 30 seconds (if even), and then immediately goes to a trickle. This is true of every faucet in the house. Worse though in bathroom, but bad everywhere. We can't even do a load of laundry. If you flush the toilet, sometimes water won't even run anywhere else. We also replaced the capacitor (sp?). I don't know if this has something to do with the 30/50 switch, or the pressure valve on the water tank. Please help. We can't afford a plumber, and need to know how to trouble shoot this at the very least.? :'(

I would look at 2 areas first, the cross at the tank, and the pressure switch. When you disturb the piping, it is possible something gets knocked loose and travels to where it catches, almost blocking flow. Likely you have a 4 way fitting at the tank, water from the pump, water to the house, water to and from the tank, and the pressure gage. Watch the gage through a pump cycle. The pump should start when the water pressure goes down to 30. The pressure should rise to 50, and the pump shut off. If it does, the pump, gage, and pressure switch likely are all right, look for an obstruction starting at the 4 way fitting. This is especially true if the gage shows 50 and it takes a long time for the pressure to go down while water trickles out. I would replace any galvanized pipe in this area. I had a galvanized cross which limed up hurting my water flow. The brass crosses I found were expensive and not the right size, so I just used a couple of PVC tees.

If the pump is shutting off before the gage reaches 50 or starting before it drops to 30, I would replace the gage first. They are fairly cheap. If the pump stops while the pressure and water flow are still low, check the switch. Also make sure the pump isn't stopping while the switch is still on. It could be defective, or too small and overloading.

Do you have a filter? I mean a housing that has a filter cartridge in it, not a water softener. The cartridge could need replaced. If you knocked a bunch of lime loose changing the pump, it could have filed the filter. If so, be glad the filter caught it before it got all through the house.

If this isn't enough to help you fix the problem, come back and let me know what you did find, and I will try to help. These things are hard to do over the net.

Labman gave you some places to check out. Let me add a few more. There are a few things he failed to address. One would be a clogged well point, with a clogged point you would have pressure for a short time until the water that was already in the suction pipe was gone. Then pressure and volume would suddenly drop off to almost nothing. The next is cavitation, (sucking air) If the water level in your well was low you would have pressure and volume until the level fell. Then the pump would cavitate and you would loose both your pressure and your volume. The well would then gradually fill until the next draw down and repeat the process. Just a few more places to check. Good luck, Tom

:o?? :(
First, thank you very much for your information. We are going to try these things. I wanted to give you some more info, which might help narrow things down some.
The pressure switch is doing as it should, starting at 30, and stopping at 50, and then back down again... and so on and so forth... however, this process happens very quickly, it drops to 30 in about 10 seconds, if.. and then it rises back up to 50 in maybe 3 seconds max. This process happens over and over... and the pump runs for like 2 second intervals every 5-10 seconds. This doesn't seem right to me. I know for certain that our well isn't low. We have a very high water table. In addition, it doesn't seem to me like the holding tank is full, ever. When you knock on it, it sounds hollow, not at all the thud you get when you knock on the hot water tank. It's almost as if the gauge is reading that the tank has pressure, but it doesn't, like the water we are using is being sucked straight from the well.
I don't know anything about this subject, but wanted to give you all this added info. Also, just to let you know, we do have a large water softener system, although I think it is not related... the main water tank seems to be where the problem is. We do have very hard water with an extremely high iron content. But all of the pipes inside of the house are under a year old. The pipes leading from the cistern to the well are old but sound. Hope this can lead you to a more distinct conclusion, and any additional feedback would be tremendously appreciated.

Much thanks and gratitude to you both. :) :) :)

Speedball has a lot more experience than me. He has some good ideas. This fast cycling suggests to me that the pump, switch and piping from the well are working fine. I think the problem is between the tank and the house. If you can, open the line at the tank, and at the softener, and blow air back through. This could expel lumps of mineral deposits knocked loose when you worked on the pump, which caught somewhere and are limiting your water flow. You could even check the screen at each faucet. Usually the end of the faucet will unscrew and have a little screen, and a spreader. Carefully note how it is put together and reassemble it after cleaning the screen. Many softeners have a bypass. If you have one, open it and see if that improves flow. If so, you softener may be plugged. Check its piping. Be careful running water or air back through it. Softener tanks are filled with plastic beads. You could wash them out too.

Your pressure tank should be part full, water in the bottom, and air in the top. Newer tanks have a rubber bladder to keep the tank from losing air. A lack of air could cause the fast cycling, but shouldn't cause flow problems. If it seems to be empty clear to the bottom, that could be where the plug is.

Once you have things working, I would install a filter between the softener and the tank. It will stop crud where it is easy to find and fix.

Hey Moon, Labman's much too modest. ::) Since we can be on the job to check and analyze the situation we attempt to cover all the bases.? Labman's done that and more. :-* Said exactly what I would have and gave you the same advice that I would have. I wouldn't have minded having Labman on one of my plumbing crews here in Sarasota. 8)

:) ;) :D ;D ;D ;D ;D ;D :D ;D
Thanks so much for all of your advice and help. I think you two are the greatest. Your final verdict was correct, their was a blockage, and it is now fixed, and I CAN GET A SHOWER AGAIN!!
In all seriousness thanks for all your help. I think this is wonderful, that you can go somewhere like this, and skilled and knowledgeable people like yourselves are willing to help out. I owe you. ;D

Thank you for getting back with us. So often I give what should solve the problem, and I never know if the person tried it, or if it worked.