Reef Octopus Classic 150SSS Protein Skimmer

In-sump protein skimmer with a small footprint, 7.3 x 9.45 in, and an Aquatrance 2000S pinwheel pump. Its Amazon page says for aquariums up to 210 gallons. Aquarium Depot's page gives 210 gallons at a light bioload, 180 medium and 120 heavy, and a sump water height of 7 to 8 in, and it's listed here at the medium figure.

Filtration

Skimmer

Max tank volume

681.4 L