Most people I have seen report the pump wearing out pumping too much sand through it and give up. Have you considered building a jetting suction line like the sand barges use to dredge sand from rivers? Pump would not have the sand /muck passing through the pump. Just need 6-8" pipe with a slot cut in the bottom then attach or weld say a 2" pipe down the side put two 90s and swedge it down from 2" to say 3/4" run it about 12" up your sucking pipe. If you can get enough pressure and volume it should work well.