I'm collecting equipment to set up my 2nd planted aquarium. I have a 75 gallon tank that I plan to run two XP3's on, one at each end of the tank. Right now my 26 gallon bowfront is running one XP3 with an in-tank heater. My goal on this set-up is to keep as much equipment out of the tank as possible.

Does adding the Hydor on the outlet reduce flow? Would a 300W be sufficient or should I run two, one on each XP3?

I haven't settled on what media I will run in the filters yet. I was considering using one sponge, Purigen, some type of polishing media (Rena Micropad) and a Hydor heater on one of the filters to keep the flow up. The 2nd XP3 I was planning on maybe two sponges, some type of biofilter media, stars or something and an external C02 reactor. If I add a second Hydor on this filter, would I be losing much flow?

My 26 gallon tank has nothing in-line on the outlet so I have no experience attaching anything inline to the XP3, and the impact to the flow.