Large Sump. What to put in it?
 

I've got a large Sump for my 240 gallon tank and have a separate compartment that was designed for a refugium. I'm wondering if people have other low maintenance ideas on what to do with the area? Looking for something different/unique than the usual chaeto.

Cryptic zone maybe?

What does your system lack? Theres no point in attempting to grow a macro algae if you're already using GFO effectively. Just as there wouldn't be much point in creating a deep sand bed down there if you've got an oversized skimmer and a boat load of live rock. Perhaps you don't have a frag tank... you could put frags down there. Or maybe you've only got one display tank. If thats the case then that extra space might be nice for a problematic fish or invert later on down the road. I like to keep a few extra pieces of live rock in my system for future use when aquascaping. Extra sump space is perfect for those. Cryptic refugiums are another option... the list goes on.

Xenia nutrient export?

Black Tip Reef Shark nursery? I know a buyer.

I always though of having a refugium as a separate display item, if it wasn't going to be used for nutrient export. Make a window in your stand and have a light under the cabinet to light it up. Put critters in there that can't be in the display tank! Make a lion fish tank, or an eel tank or something out of it!!!!

Unless you need it for a specific reason just use it collect detritus and vacuum out as necessary. Doesn't get any more low maintenance than that and won't turn into a phosphate factory.

If I pick up some pods from a pet store and throw them in this section, would I need to get them some kind of food to survive or just eat the small particles that find their way in?

I've had my fuge area set up as a temporary frag system before. Similarly used it to keep mandarin goby and now some rescued baby cuttlefish that hatched at LFS and would have died in the store without any live food. Hopefully at least one of the three still survives hunting down my live pods and mysid shrimp in the fuge.