I have a sandpoint well. When I turn the tap on, the pump starts immediately with good pressure but the pressure drops off very quickly. I have checked the bladder and it seems okay. The pump takes 5 - 10 minutes to get back up to pressure (60PSI). When the pump runs, it sounds grainy. I am wondering if it might be a crack in the impellers causing the long pump time. Once the pump starts, I cannot get back to pressure unless I close the taps, wait a minute, then turn them back on. How can I check the impellers on the pump? My thoughts are that if it's not the impeller, I might have a low water level in the sandpoint. Any feedback would be appreciated. I've attached a pic. It's a Berkeley Model 5HS.