I have low water pressure. I called a guy and he said I have undergrond leak. They shutthe valve off and turned it back on and I had even less pressure. After a couple of days the pressure came back to where it was before I called, not great but back. If I have an underground leak how am I getting any water at all? There are no wet spots in the yard either. I can hear air in the lines and sometimes it sputters.

Just how did he determine that you had a leak?
Do you have a check valve between the tank and the well?

Is the pump above ground or in the well?