Pump for bio-pellet reactor

[xiaan]

I currently have the Next-Reef SMR1 Bio-pellet reactor and I was using my return pump to power the reactor. I wanted to switch to a dedicated pump for the reactor but I have been having trouble getting the right flow rate through the reactor to make the pellets tumble correctly. I have tried a EHEM 1250 and a Water Blaster HY-2000 both did not give enough flow to tumble to pellets correctly.

I am wondering what people are using for a pump and what flow rates they are using.