Pool pump not holding pressure

Hi,
Just opened my pool for the first time by myself. I have a DE filter and checked all the seals and o-rings. When I started the pump, I had the air valve fully opened as indicated. When I had a steady stream flowing thru the tube, I had water coming out of the bottom of the filter. I closed the air value and immediately lost all the water into the hose. Pressure is at 4PSI when it should be at 10-12. Completely tore apart the filter and the handle control and all seals and o-rings double checked and verified as in good condition and seated properly. I attempted to check the impeller but either can't locate it or can't fit my finger in it to determine if there is debris. Any suggestions?

Thanks!

The most common cause of a pump losing prime is a suction leak, allowing air to enter the piping. Places to check:

1. Thread entering pump.
2. Valves between pump and skimmer/drain
3. Unions between pump and skimmer/drain
4. Any fittings for a feeder or other device connected between pump and skimmer/drain
5. Pump winterizing plug loose.


. . . membership updated.

I am having a similar issue w. a Krystal Klear Intex Sand pump. I am going to check the threads and valves
you mentioned. Not a lot of air bubbles visible, but just not pumping like it did last year. Pump is now a year old.
Thanks for any additional suggestions.