55 Gal FOWLR - seeking criticism

[turbo]

Hey I just thought of something. What if the PVC drain that is destined for the refuge is piped into the cabinet through a hole that is lower than the top of the sump by 8" or so? It would have to climb uphill and then it could drain freely into the sump.

I suspect this would greatly reduce the flow rate of this pipe without restricting it mechanically???

I dunno am I missing something here? Part of the reason why I want to do this is because one of those holes that I already drilled (see pics) is now going to be lower than the top height of the sump tank, but I still want to use the hole.