Classic 100 HOB Protein Skimmer

The Reef Octopus Classic 100 HOB Protein Skimmer steps up the Classic Series' hang-on-back design for aquarists running larger single-tank setups without a sump. Water is drawn through a needle-wheel pump and sheared into fine bubbles inside a cast acrylic reaction chamber, giving dissolved organics a huge surface area to bond to before they're carried up into the collection cup as dark, concentrated skimmate. Best for: reef, FOWLR, and mixed saltwater tanks up to approximately 105 gallons Setup: external hang-on-back mount — no sump plumbing needed Pump: self-priming needle-wheel pump for consistent microbubble production Maintenance: removable cup and riser tube for quick weekly cleaning It's a natural next step up from the Classic 90 HOB when bioload outgrows a smaller skimmer, without forcing a switch to an in-sump model. Export capacity scales with the taller reaction chamber, so contact time — and skimmate yield — goes up along with tank size. Compatible replacement parts: Classic 100/1000 HOB series pumps and collection cups.