I recently bought a house and and the onwers didn’t cover the pool over the winter and we aren’t 100% sure they winterized it. The water level was low enough to indicate they did. Anyways, sincle we moved in, we haven’t been able to get the pump to prime fully. There is air in the system. The jets blow out lots of bubbles and blow in bursts. I have greased the O ring on the pump lid and I made sure the O ring at the union was intact. At one point the jets were blowing harder than before and we tried to clean the pool and after about 20 min the hose lost suction completely and the jets were barely blowing. We hooked up the hose the correct way by filling it with water and connecting it to the skimmer without raising either end out of the water. The pressure gauge on the sand filter is constantly between 15-20 psi. When the pump is running, there is a gap that varies from 1-2 inches between the pump lid and water level. At the top of the sand filter, there is a steady noise of what sounds like water swishing around as if there isn’t a steady flow of water. Please help!