Holy swiss cheese
Are they using 1 inch glass for the bottom?
I would go with a two inch close loop intake or a second 1.5 inch intake, the Sequence ReeFlo series pumps have 2 inch intake.
My Oceans Motions' 4 way does not like sand or any type of debris, more than a few people I know have the issue with sand binding the internal drum. Having the close loop intake facing up wards will only further exaggerate this problem.