1500GPH and two(2) 3/4" returns - enough flow?

[CrAzYNeSs]

When you work with plumbing lines of that size (less than 1") flow changes a lot with reduction of cross sectional area. But if you plan on using 3/4" line try to keep 90degree bends to a minimum. You can search online for flow loss due to bends. there are flow charts and tables which have already calculated the equivelant loss through length of pipe for any connection (90 or 45 elbows, couplings, etc...)

Could I do 1" plumbing all around and just use the ball valves to control flow (as advised earlier)? And at the end have a 3/4 reduction for the return/outlet. Would that be a better solution to this problem?

 

[rhodes_96]

I use the same pump on my sump and use 1" return to the tank. Runs about 4m of 1" pvc from the pump return to the aquarium. I have 4, 90 degree bends. The flow is very good. Running two outlets I am not sure as I haven't tried it.