how to hook up an inline pump?


Guru Class Expert
Jan 22, 2008
Vista, Ca
I cant seem to find the answer on google. Is it possible to simply purchase an external pump and place in line with my eheim 2026 and diy external reactor? Will it slow down the flow? Speed it up? Strain the eheim ect..? Thanks, the reason for doing this would to A) Increase flow into the reactor, B) Increase flow into the tank.



Prolific Poster
Jan 18, 2009
Bellingham Wa
Im doing this with a dedicated fractionating external pump, but not inline with my ehiem. Why do you need to put it inline with the canister? Two outlets into the tank will get you better more options for good c02 circulation to all parts of the tank.


Guru Class Expert
Dec 15, 2007
How big is your tank? I have a Eheim Pro 2 2028 for my 110g tank an that only pumps out at 275gph. I ran my CO2 Reactor and Hydro Heater with a Mag 5 500gph Pump inline with it's owe intake and return ,
IMO you will get better results that way with your co2 instead of adding head pressure loss to the filter, you will have better circulation in your tank. Even then you should have at less 10x turn over rate in your tank you might have to add a power head to give your co2 good circulation.


Plant Guru Team
Lifetime Member
Sep 23, 2007
South Florida

I echo the other replies:)

If you do it your way, you will have a lot to worry about with matching the flow rates based on where you are placing the other pump.

I would just run the reactor as said on it's own pump. Let the filter do it's thing un-impeded and drive the reactor separately.

You can always splice the reactor output to the canister outflow but increase to a larger diameter pipe AFTER the splice as you will have more flow..........

That way there is still only one pipe to the tank. That said however, it is better for circulation and flow to have separate outlets, maybe one on each end of the tank.

IMO you will get much better results..................