Yes! Water! Do you see any restriction in terms of return pump performance from those 90's?
Any restriction seems pretty minimal. The pump is a bit over powered to begin with so it's really not too noticeable. It's an adjustable pump with 6 speed adjustments. Right now it's only on the second level. I wanted to keep the stand nice and open not too obstructed with plumbing to do this I needed to run it that way.