I notice lately that the water coming out of the shower or spigot, tends to speed up and slow down rather than just run continuously at a steady rate. It seems like my pump is kicking on more often. I checked the pressure on the bladder tank, and it is at 25 pounds, which I assume is adequate. There are no leaks that I know of and the pump doesn't just kick on for no reason (such as a leak might cause) Is there anything else I should be looking at? What other things may fail or wear out that would effect water pressure in the lines?