How to plumb Octopus

[mobie]

Trying to figure out how to plumb a Octopus recirc externally.
The feed should be no problem with a overflow setup, I 'm figuring
300 gph on a 180, it says 1.5 times system volume.
But, how do I get it back into the tank with no sump?
It's a Octopus DNW 200 Recirculating Skimmer.

 

[mobie]

Any ideas?
Here's my sich, got a 180 with no sump, right now I have a prizim pro HOB and It's not doing a good job.
Looking for options

 

[stingythingy45]

You're going to need some kind of a sump.

 

[JasonandRay]

make a sump =] and overflow out of pvc