Canister to refugium flow in reef tank

[sfranqui_29gallon]

Right now I am starting a 75g reef tank, for soft corals eventuially.

I have the tank going from a rena xp2 canister filter to a 30 gallon refugium with a 700 gph return pump.

I have an overflow box that seems to have stopped. Is it because the canister intake is good enough? Should I adjust anything? I'm worried about flooding if power outs. Any suggestions. Is that enough waterflow?

Thank you thank you.

 

[CA-Delta]

Two pumps, one circuit, that makes me nervous.

 

[sfranqui_29gallon]

Its really just an intake motor and a return motor. What's the potential issue? How can I hook up the canister to the refugium? Refugium is about a foot away and on the same level as canister. I already tried but not enough gravity. Any suggestions?

 

[CA-Delta]

There are a number of potential issues. You may have discovered one of them already.
If I understand correctly your XP 2 draws water from the aquarium and returns it to the sump.
At the same time you have an overflow box that presumably also supplies the sump.
When you say the overflow has stopped , do you mean it looses prime or is just not flowing much water ?
Why do you want to hook the canister to the sump ?
If the power goes out the canister circuit could drain the aquarium as low as the canister intake level.
If the sump return pump fails the canister will keep running until it's intake is exposed.
If your canister quits and the overflow fails to start, your return pump will burn up.
Why not use the canister as a stand alone system and leave the sump/overflow alone ?