I recently (2 weeks ago) installed a Nu-Clear canister after my Cobalt canister filter,(used for mechanical filtration) connected in series using a Sicce 2.0 pump after the Nu-Clear canister,(Biological filtration) using it as a return pump. From the pump, I installed a CO2 difusser, a quick disconnect ball valve from Buce Plants and the return lines were split back to the aquarium for better distribution of CO2. In hindsight, I would have measured the return lines equally from my "Y return. Overall, flow was reduced quite a bit. I thought a larger GPH pump would suffice. 2 weeks in, all can say is WOW! Water is crystal clear and the plants are taking off. The Tetras favor the higher flow return side of the tank.