my reactor is different from yours. mine does not have the diffuser. co2 is just fed from the top and it has 3 bioballs in the body.
anyway, you can do the tom barr venturi modification. do a search on his site
www.barreport.com for "internal co2 reactor". but this mod will increase misting so it may not appeal to you.
i used a dedicated powerhead attached directly to the reactor. it was a 200l/h powerhead. gave good flow in my 20h, but was not dissolving/misting enough co2 for the tank.
i think this reactor would be good for a 10 gal tank, with a slower flow through, but it would take up too much space in a tank that size.