guys, i'm using a sump filteration, therefore i have an out flow pipe... now the pipe is situated 4" below the water surface where total water height is 24"

at the bottom of the tank, i have a reactor blowing out..

how deep should i place my outflow pipe?? is 4" fine or lower is better...

both co2 reactor and outflow blows at the same direction...

**was thinking to place the outflow lower to help distribute dissolved co2 around the tank since the reactor is not powerful enough....

is it recommended?