1/2" to 0.5mm valve?

[mrhasan]

Originally Posted by hillegom

from 1/2 in to 0.5mm is a big restriction. I would buy the smallest pump I could.
You could always cap the end of the 1/2" pipe and drill a 0.5mm hole into the cap. But I bet you will be enlarging the hole pretty darn quick. Big back pressure on the pump!

I might be wrong about the hi-end pumps but isin't all the powerhead pumps's mouth 0.5"?