Thats great, but the way you have it now... you are in effect routing your CO2 thru the powerhead and into the water. The "difusser" has in effect become inoperable. To be using the difusser you would be "pushing" the water thru the difusser, not "sucking" the water/CO2 thru and into the powerhead. Either way you seem to be accomplishing the objective.
Eheim pimp #128, 55gal 13x20x48, Eheim Pro 2227, CO2 injected, into the filter breather tube,4x 55w Pcs , 12 hr light cycle (sunrise/sunset simulated), Milwaukee SMS 122, faulty bubble counter replaced with M3 bubble counter..... moderately Planted, Plantex CSM+B and ferts
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