I just bought a house with a pool rough 20 years old with newer plaster and my pump was shot so I installed a new Hayward Ecostar on a sand system, pump would auto prime no problem for first two weeks and now it won't and I cannot run it faster then 2000 rpm without bucket being 1/2 empty but while on low speed bucket is full. Skimmer level is fine and I can't find air leak on 2" pipe, could the check valve before the pump be blocked up with debri from vacuuming ? I also have a black algae prob, first shocked it
Then used black algae killer and no prevail twice!
Pool size is rough 25k