The water pressure in the faucets, toilets, shower, etc recently started to fluctuate. I have a well with an 9 year old pressure tank. The tank reads 50 psi and rapidly changes from 40 to 60 psi when the water is turned on. Changing the water filter did not alleviate the problem. Is the tank bad or can it be the switch? How do I checkand fix?

Check the pressure tank by popping the air valve on top of the tank. If water comes out then the membrane's ruptured and the tank must be replaced. Another way to check to see if it's waterlogged is to tap the tank with a wrench or a pair of pliers. There should be a "clunk" about half way up changing to a "clink". If it "clunks" all the way up replace the tank. Good luck, Tom