Upgrade time !

[RDNanoGuy]

It's always a good idea to mock up your plumbing before you glue anything together. Also it helps you to make sure you have shut off valves and unions in all the right places so you can service your equipment.

The pump choice is determined by the amount of flow you want through the system. Most aquarists' like to run about 5 times the display tanks volume through the sump per hour. Also when choosing your pump don't forget to account for the head loss due to the height back to the display. Most pump manufacturers provide a chart to help estimate the loss for a given height.
Also add maybe20% more to account for the flow you will divert to the refugeium.