In-line needle wheel pump for use with XP3?

Hi all,


I'm looking at options for diffusing CO2 into my 20 gallon long.


Currently it is filtered by a Filstar XP3 (minimal media... right now tank has no fish).


I've tried different methods of CO2 delivery on this tank and would like to plumb a needle wheel pump into the return of the XP3. I had read a few years ago about people doing this with success, but either I can't find the posts, or the needle wheel pumps are no longer available. Can anyone offer suggestions regarding a compatible pump?


Regards.

 

So the XP3 is rated at 350 gph (I assume that is with no media... I'm running mine with a single sponge pad).


I see the Danner Mag 3 needle wheel pump is rated at 350 gph as well. I assume that if I install the Danner on the outlet side of the XP3, the output from the Danner should be approximately 350 gph (since it is in a closed loop, the output should not be affected by head... correct me if I am wrong).


So my plan is to insert the Danner needle wheel pump on the return line on the XP3, inject CO2 into the line right before the NW pump, and see how that goes.


I guess my questions are:


1) I suppose I wouldn't even need to plug in the XP3... correct?


2) would it be worthwhile to forego the Mag 3 and just go with the Danner Mag 5, which offers 500 gph? I'd likely put a ball valve on the tubing after the NW pump. Tank is a 20 gallon long.


Thanks for any input!