question about flow for my 29gal tank plz Help!

[HiReV508]

wondering what size mag drive pump should I get for a return for my 29 gallon reef tank, I just built a 10gal sump but I'm having trouble deciding what size pump to get......Mag 3 Or Mag 5? what you guy thinks?

 

[Turbosnail]

I would go big and throttle it back with a Ball valve just in case later you want to add a bigger sump or branch off to a refugium or run a reactor for carbon or gfo.

 

[HiReV508]

just did a little research I think i go with mag 5 I just order it hank turbosnail for the help!