I built my pool 3 years ago and what seems to be normal for me, might not be correct. After the pump turns off, the water goes back into the inlet side (pool strainer or drain) and the pump becomes partially full. Is this how it should work? Or should the pump filter basket always be at full capacity? I do see bubbles in the returns quite often. Could this be part of the issue showing itself?
It seems like it puts a lot of strain on the pump every time it turns on because it has to re-prime itself back to full pump action.
Also, how often do we check a sand filter? It has been three years and I was wondering if I should open it up and look at the sand level? It seems to be filtering the pool just fine, but didn't know the clean/replace schedule or even a checkup time.