For the folks with wells, you may want to check the psi of the air bladder in your holding tank. Over time these can bleed down,also depending on your location,temp. can also effect these,most require 3-7 psi. There is a one way valve at the bottom of the pick-up tube which can also go bad over time allowing pressure to bleed back,making your pump cycle a great deal more than needed,this can lead to expensive repairs or replacement.this can be checked by watching the psi guage ahead of the holding tank,if this bleeds back after your pump cycles more than 5 psi in 30 minutes with no water usage,look into replacing the valve. Most well systems have large amouts of calcium and lime, a good in line charcoal filter installed ahead of the holding tank can save alot of headaches with build up in your valves and related hardware