Best way to add a second tank into a system?

[kdx7214]

I've got a 75g DT + 40B sump. I've recently been given a brand new 20g tank that I'm thinking of setting up as a secondary to the main DT. Plan is for a macro algae tank to act as a "display" refugium. Right now my sump flow rate is far too fast for macro algae (the chaeto I put in has been slowly torn apart and plugging my filter socks lol).

My initial thought would be to put a small powerhead in the 75 and pump water over to the 20G, then an overflow return to the sump. What would be the plus/minus on something like that? Any advice?

Thanks!

 

[KonradTO]

I mean if you can drill I would do exactly the way you said, given that you can place the 20g above the sump..

 

[Arego]

I did this with a 10g years ago. I drilled a one inch hole about a inch below the top setup a bulkhead and rain a drain right to my socks. As the 10g filled from the return it would gravity feed through the hole right back to the drain socks.

I used an mj1200 with a gate valve on it to determine best speed. Just make sure when power is off your sump can handle that back flow from the 20g too until the siphon breaks.

 

[X-37B]

I would get a tank with a corner overflow or drill one.
I did this on my 120 and its still plumbed into the new 80g.
My display return uses ball valves to control the flow.

 

[kdx7214]

Thanks everyone! I'm planning to drill the 20 so that shouldn't be an issue. I'll have to readjust water levels in the sump to make sure it can handle all of it, but I'm going to do my best to have the overflow in the 20 at water level.

Cheers!