Just common sense here, if the sand is in suspension it could wear the impeller and bearing surface. If you've cleaned the sand well, and/or use a more course sand, a pair of convicts should not kick up the sand. (course sand will settle almost immediately)
Use mjryan & MP's good advice.
How about a pic?...
Dr Joe
.
Use mjryan & MP's good advice.
How about a pic?...
Dr Joe
.