I have just bought a sump and a mag 7 for my 30gal. I'm used to all in one systems "nano cube". I also have a overflow box. How should i set up the return system? Tubing? Hard PVC? Ball Joints? I have no clue. What do i use for a return nozzle? help
I agree with Skene, a mag 7 is to much for your needs you will end up dialing back ( placing a gate valve) on the return to slow the return flow. maybe a Mag 3 would be just right even a 5 with a manifold to feed other items would still be enough. whats the size of the overflow?
Without knowing your back pressure (vertical lift + plumbing fittings) it's impossible to accurately size your pump. IMO the Mag 7 would be perfect if you're going to manifold it for other equipment with reasonable back pressure.
Your overflow from the display needs to run to your sump without any ball valves or gate valves. You want this run of pipe/tubing to be unimpeded.
The return from your sump should go from your pump > union > ball valve > LocLine return fittings.