Considering a separated sump and fuge.

[Dans85]

I'm in the planning stages for a 45g cube which is mostly a diy project. I'll be building a stand that is going to be 30x30. With such a small footprint I'm pretty limited on the size of sump that I can have which will most likely be a 20g high. I am considering adding a second 20g next to the sump for a fuge that will be fed by the return pump and will be connected to the main sump with a few bulkheads and a short length of pvc. I am hoping to have as large of a fuge as possible because in the future my wife would like to have a mandarin.

I have also thought about adding a second tank just like the fuge idea, but have an ATS instead and use a descent amount of LR as "pod condos"

Does anyone have any thoughts on how to plumb a setup like this?

[reefer1970]

I have a 30g refugium joined to a 30 g sump by a 2" bulkhead. 125 DT has one drain into fuge, other into sump. Fuge flows into sump, then return pump sends water back to DT tank. Skimmer is in first compartment of fuge. Algae scrubber in rear compartment of sump. so flow is : drain on left-skimmer-fuge-2" bulkhead/ pipe-sump-return pump (second drain on right goes into algea scrubber-sump-return pump. hope that's not too confusing

[Dans85]

I think I have a pretty good picture of it. Is the pipe connecting the two level or is it angled?

[slief]

That's how I designed my sump and fuge are setup.. I had to go that route to fit the new setup under my tank via the two pre-existing door openings. I wanted them as large as possible which necessitated the 2 piece design. I also included a bypass line so I could shut the fuge down for maintenance without having to shut my return pump off.

The design has worked out very well. The ability to isolate the refugium allows for easy maintenance without shutting the system down. The refugium houses a deep sand bed with mud, sand and live rock rubble along with macro algae. Both the refugium and sump are covered to minimize evaporation.

This is the design I came up with. Obviously much larger than you are planning but I'm sure it might give you some ideas. It's worked out so well after running this for 6 years that I wouldn't change a thing.
http://i390.photobucket.com/albums/oo347/shleif/Tanks/Sump%20rr/sump-and-fuge_WEB-1_zpsacd37f69.jpg

This is the finished product. I did most of my plumbing in advance so the install was simple and quick since I was removing my old sump setup installing this into a fully stocked tank without draining it and needed it up and running the same day. The sumps are connected via a pair of 2" bulkheads with union ball valves in between so they could be easily connected below the tank. You can see the bypass line running in front of the refugium.
http://i390.photobucket.com/albums/oo347/shleif/Tanks/Sump%20rr/Sump-and-fuge2_zps46e073c1.jpg

This is how the refugium bypass line connects to the return pump. I close the valve nearest the return section of the refugium and open a valve near the first sump.
http://i390.photobucket.com/albums/oo347/shleif/Tanks/Sump%20rr/Pump_zps07d7e3a7.jpg

http://i390.photobucket.com/albums/oo347/shleif/Tanks/image_zps8zke2otm.jpeg

[Dans85]

Your setup is very similar to what I have in my head just on a smaller scale. Thank you for posting pics. I really like the idea of the bypass.

[slief]

Your setup is very similar to what I have in my head just on a smaller scale. Thank you for posting pics. I really like the idea of the bypass.

Glad to help. I've only used the bypass once or twice in the last 6 years when I messed with my macro but for those couple times, I was glad to have it. As such it was worth the effort to include. I have a bubble trap at end of both the sump and refugium. The one at the end of the sump wasn't really needed but the one at the end of the refugium is. I would suggest including something to keep snails and any macro out of your pumps. As such, some sort of slots or mesh between the region and the return section where the return pump will reside should be included in your design. In my case, I have a false wall running across the entire front and back side of my refugium that has vertical slots for water to pass through. It prevents critters from making their way into the return section of the refugium and also insures that the flow into and out of the refugium travels across the entire width of my refugium in a laminar sort of fashion.

You can see the slots in this picture as well as the first one I posted above. I also have a deep sand bed in my refugium so in my case, the slots start 6" off the bottom.
http://i390.photobucket.com/albums/oo347/shleif/Tanks/Sump%20rr/DSC01006_zps6ee36fa3.jpg

[Dans85]

I was thinking about using an overflow overflow box that surrounds the bulkhead on the fuge side to help minimize algae and critters from getting into the sump.

[slief]

I was thinking about using an overflow overflow box that surrounds the bulkhead on the fuge side to help minimize algae and critters from getting into the sump.

That could work.

[Legot]

My tank isn't running yet, but I have a 20L as the sump and a 20H as the fuge for my 33L DT.

The 3 DT drains go into the sump in-section (middle of the stand), then water passes through the sump to the return section (left side of the stand). The return pump then Tee's off to the DT and the Fuge (right side), and the fuge uses and overflow box with a herbie drain back into the in-section of the sump.

From testing it seems to work pretty well! I wanted to avoid having the sump and fuge hard plumbed together since I was using glass tanks and in case I ever want to replace the fuge with something else. It also allows me to keep the sump and fuge running if I ever redo the DT.