Hey Kamil,
When you say to run it inline with my return, did you mean to have all the flow run through the sterilizer, then return to the tank? I'm running a Gen-x40 return pump (also supplying water to chiller), so I think that'll be OK for the sterilizer.
EDIT: I was just reading the owners manual, and answered my question. In-line is the way to go, with all the water passing through the sterilizer.