I have a 84ft well installed in 1995 with a Marley Pump and A.O. Smith Aqua-Air model V100 tank. The pump kicks on at 20 and off at 40. When the pump first starts it sounds normal as in the past but for the last month there is a swirling sound as water is entering the tank. Once the pump kicks off the gauge jumps to 47 then settles back to 40. When the pump first shuts off there is a sloshing of water(sounds like dripping water inside of the tank only for a few seconds).Is this something that is of concern and how can it be stopped?