Hello all. This is our first house with a well & septic system. The well pump(submerged) is approximately 18 years old and has never been replaced to my knowledge. We are now experiencing very low interior house pressure when outside spigot is in use or when washing clothes, showering, etc. involving extended use of water. The holding system seems to be turning off/on and backwashing appropriately. Pressure in holding tank is approx. 35#. I'd appreciate any clues as to how to diagnose the problem. Thanks in advance.
Michael

What are the pipes in your house made of? Copper?: Galvanized or Plastic? How old are they?
The holding system seems to be turning off/on and backwashing appropriately. Are you referring to a galvanized pressure tank, a bladder tank or a water sodtener? What's a holding system and why is it turning off and on? And what are you backwashing? I can tell you how to increase the pump pressure but if you have a volume problem that's not going to do much good. Answer me and we'll take it from there. Regards, Tom

"We are now experiencing very low interior house pressure when outside spigot is in use"

Is this problem a change compared to what you initially had in the house or has it been this way from day one?

I think SB is hitting the nail on the head with his comment about volume.