new 30G set up

[QAScooter]

Kabal's got a good point. You don't want a lot of water flow through the refugium, hence the smaller pump. Then beef up the movement in the tank with PH's.

My tank is only 24" wide by 16" deep so I don't want to add any extra PH's in my tank, as well as noise/humm considerations. Then there is the added heat....

 

[MX6import]

there is no refugium.
and I was just on marine depot and looking at the SCWD cart and the mg chart a mag 7 will be fine. a mag 7 at even 6 feet which it wont be that high will give me just about 320GPH into the tank. that is including all the elbows. a mag 9.5 a the same height will give me about about about 600GPH out into the tank. that's a big difference.