Tbf ive left a gap around the outskirts of the whole tank so flow can get through. I could do with lowering my intake pipe from my fluval cainster. Its a bit short coming from a shallower tank.It looks really good I'd be the same now if I had clear sand lol. One thing you could do is (and sorry I know you've just rescaped lol), not hide the inlet pipe. If its got clear flow from the tank it will suck out more If you are not too keen on the standard pipes you could look at getting the steel ones which look a bit cooler.
Wills
Might upgrade the fluval once my aquael is well established.
Ps hows your puffers settled?