Tell a beginner about sumps:

[vlangel]

My tank was an AIO and I added a sump. The 30 gallon with the clownfish is my current sump but I also partitioned off a 20 gallon long and used that when I used a skimmer. So super simple sump or a complex one, they can all work.

I used a HOB overflow box to get the display tank water to the sump.

 

[AlexandraDreadlocksPanda]

I would never be without a sump. I’ve got a Red Sea rollermat 1200, big Deltec skimmer, Euroreef Calcium reactor and a live rock fuge in mine. Also have about 8 plastic bath scrunchies in a net bag that the carbon gets dosed into… provides a low flow area for the bacteria to colonise and stops it slugging up your return pipe with pink snot.

 

[Blue Spot Octopus]

^^^^^There is nothin that says old school than EuroReef. That is hard to find in the states.