Starting a sump

[argan]

you have an overflow i assume? I would slowly pour the water into the display tank , letting it drain into the sump. I would go for around 5 gallons a minute adding the new stuff.

And it goes without saying but make sure the SG matches as close as you can, i did a water change the other day where i messed up and made the new water too salty, and had a carpet surfing clownfish!

[Treebeard]

My sump will be in the basement, as is the RO/DI water, and the display is on the main floor. I think it would be easier to restrict the flow from the return pump to a few gallons a minute rather then carrying all that water upstairs.