For whatever reason this never showed up , so I am going to try sending
again
Gale :~)

I use a larger *outflow* BH than for *inflow* - a 2" BH will handle up
to
~ 2000 gph , although more than ~1200 gph is pushing the envelope for bio-
filtration in a 45 gal barrel
Gale :~)


So a 1" BH would only give me 500 gph?

That's probably close but I have never actually tested that - I use a 2"
bulkhead and 2" threaded hose barb nipple for the return line and a 1" or
1.5" bulkhead for the inflow line with the appropriate size threaded hose
barb nipple for the line from the pump. You can always use 2 return lines
instead of 1, but I have always used one 2" BH for the return
Gale :~)