Pretty much a novice here. 16500 gallon pool, haywood sand filter, pentiar pump only 1 skimmer and a main drain at the bottom.
I was vaccuming tonight as per normal, pressure read on the filter 10 psi as it usually reads. I backwash it regularly and clean all the baskets 2-3 times as week, plus my pool is not near trees.
Tonight I was vacuuming and the pool vaccum head sudden stuck to the bottom and I had a very hard increase in suction. I near the pump making some different noise and noticed the sand filter psi had dropped to zero.
I cleaned out the pump basket to make sure it was good, primed the pump. I did notice when i was cleaning the basket it seemed like air or water was draining from the line from pump to the filter which I never recall hearing before. Anyway, after trying to vaccum again (no air in the hose) it did it again, hard suction and pump pressure read zero.
Not sure what the issue might be. Any suggestions on where to look? I check as far as I could with my hands and don't feel any blockages in the lines, and the water level is good.