No. The return is setup so it moves the surface in the res. The flow of the return pump is very important too. Because I’m not using stones, the level of DO has to be kept saturated, so the water has to be cycled pretty fast. ~15x per hour. Keep this in mind and you can build a system of any size with one pump. You just need to make changes to how the water is disturbed as the level of DO at the end of the system could be lower but I haven’t come across this problem yet. The only change I make to a larger system is to have a little jet of water breaking the surface of the pots. This will restore any depleted DO. It’s really simple. Ppl make it too complicated. Think of the ocean. Right out in the middle of it. Do you see big airstones out there? Lol. It’s the waves that create the exchange. Flooming does the same thing except you have a pump that moves the water from the bottom to the surface to recharge with DO.

Lots of ppl on here don’t believe me ‘cuz it’s not the norm and it’s not what everyone else does. I know it works. I have less heat, less dissolved CO2, stable PH, nice healthy white/yellowish roots and rapid growth.