Grow Out Tank Flow Design Question


Premium Member
I have a new Grow Out Tank that is being made for me. I've been working with the design for the flow. Here is the design so far.


Question I have is that the tank will only be holding 50gallons of water but it still is 6'x2' but only 7" of water volume

The pump plumbed into the sump will be an Iwaki 40 which will give me about 900gph
The question is in regards to the 2 closed loops. I was planning on running two Little Giant 4's which would give me about 1325gph each bringing the total tank turnover rate to about 70x
That seams like to much.
If I use the Little Giant 2's then my total turnover rate to about 45x which is almost identical to my main display.

What do you think? I usually believe it's difficult to have to much flow but the tank will have about an inch of sand (I really do not like the look of BB - just a personal thing) so I don't want the sand blowing to much and the output T's will only be about 5 inches off the sand. So it will be really important to have the flow diffused. After it's installed I could always add another set of T's on the T and thus each closed loop would go from 2 outputs to 4 (maybe add a 45 degree to angle the flow a little)

Opinnions are always welcome!