I'm sorry for not know the specifics of my well system. I've asked and no one seems to know. I do know that it's a deep well with a submersible pump. My father in law had the well dug 30 years ago and he was told they hit granite and an underground stream and the well would never go dry. We use to share this well with the in-laws until we lost water pressure about 2 1/2 years ago. They decided to go on city water and we decided to get the well fixed. We had clogged piping. We replaced all 300 feet of line (from well house to our house) with 1 inch pvc piping and the service man replaced the steel piping that went into the well and the bladder tank. We've not had any pressure problems until this month. The water pressure is still great. However when I use the washing machine we lose all water pressure. I comes back quickly but doesn't last long unless you leave the water off for hours. Once pressure returns the water is full of iron or rust. The pressure tank seems to be holding pressure when we checked it, but no one has looked at it once water pressure has been lost. We are not sure where to begin or how to troubleshoot this problem. I now I don't have the money for the service man to come back. We've been told it could be the pressure tank or foot valve. Does anyone have any suggestions on what may be wrong or what we need to do to maybe find out what is wrong? Again I'm sorry for not know specifics about this well or pumping system.