1.5" ID hose for Mag 18?

[Broncos]

i just read this site: http://www.dannermfg.com/instructionsheets/ZG100.PDF
and it says that a mag 18 should use a 1.5" ID hose for the maximum flow...

I'm just curious why this would be as the outlet seems much smaller (~3/4") and seems like it would be constricting. Does anyone run this into a 1.5" pipe? If so, do you use Spaflex?

Thanks!
Matt

 

[Curve]

Yes the mag 18 is going to flow better with the 1.5" hose but if you size up that big I would use pvc and not spa flex. The 1.5" will be less restrictive thus providing the best flow.