Drain Size & Pump Size
 

I purchased an acrylic tank 48x24x24 drilled for a 1 1/2" drain. I
have two questions; first, what size pump would you suggest to return
the water, and what size should I drill the return(s)?

I am planning on a reef tank with soft corals if that helps at all.

Drain Size & Pump Size
 

I have 48x24x18 tank with 1 1/2 drain, and I'm running 500 GPH pump on
the open loop, but it did handle 1200 GPH nicely but very noisy.
I have two 3/4" returns that handled 1200 GPH pump (the flow was less I
imagine. It was QuietOne 4000 HH)

Regards,
Yuriy