Octo Classic 150INT Protein Skimmer

In-Sump Protein Skimmer for Sump-Based Marine Aquariums Up to 210 Gallons

The Reef Octopus Classic 150-INT is a time-tested, heavy-duty in-sump protein skimmer designed to deliver professional-grade organic waste removal for marine aquariums up to 210 gallons. Widely regarded as a benchmark filtration unit for serious hobbyists, the Classic 150-INT seamlessly balances cost-effectiveness with industrial-grade engineering. Powered by the specialized Aquatrance 2000s pinwheel pump, it draws a massive amount of air relative to its low power consumption, producing the ideal bubble size needed to pull dissolved organic compounds from the water column before they can break down into unwanted nitrates and phosphates.

Constructed from premium, heavy-duty cast acrylic, this internal skimmer features a smart hybrid cone body that tapers toward the top. This specialized shape naturally reduces internal turbulence, allowing the rising foam to stabilize and concentrate as it journeys into the collection cup. A precision gate valve assembly gives you absolute control over the internal water line, allowing you to easily adjust between dry and wet skimming depending on your system's bioload. Backed by a bubble plate diffuser that reduces micro-bubble bypass into your return pump chamber, the Classic 150-INT is an exceptionally reliable asset for any standalone marine display.

Bioload Handling

• Heavy Bioload: 120 Gallons

• Medium Bioload: 150 Gallons

• Light Bioload: 210 Gallons

Key Features

• Reliable In-Sump Profile: Streamlined footprint leaves plenty of space in your filtration chamber for media reactors, heaters, or refugiums.

• Aquatrance 2000s Pump: Draws a robust 720 L/H of air while consuming an energy-saving 18 Watts of electricity.

• Bubble Diffuser Plate: Quiets the internal water churning, allowing bubbles to lift smoothly without popping prematurely.

• Easy Adjustment Gate Valve: Raised gate valve system lets you make micro-adjustments to the internal water level without splashing.

• Effortless Cup Maintenance: Features a secure, quick-release neck seal so you can pull the cup for emptying without struggling.

Ideal For:

• Reef and saltwater systems from 110 to 210 gallons running a sump with 6–8 inches of available water depth in the skimmer chamber.
• Hobbyists stepping up from the Classic 110-INT or a comparable skimmer who need more skimming capacity for a larger or more heavily stocked system.
• Medium to large reef builds where a proven, reliable Classic series in-sump skimmer is preferred over a more complex DC-pump model.

Pro Tips:

• Give the Aquatrance 2000s extra break-in time. The larger pump and body volume of the 150-INT means the break-in period can run closer to three to four weeks than two. The 2000s produces a higher air draw than the 1000s, and the bubble column takes longer to fully condition and stabilize. Set the gate valve at mid-range and resist adjustments for at least two weeks.
• The 6–8" sump depth range gives you more flexibility than the 110-INT. The 150-INT can operate at shallower sump depths than the 110-INT's required 7–8" minimum. If your sump runs on the shallower side, this model accommodates it while still delivering the capacity step-up you need.
• Consider a waste collector for busy systems. At 210 gallons light bioload, this skimmer can produce a meaningful volume of skimmate daily on a well-stocked reef. The 4" or 6" Waste Collector with Auto Shutoff (listed as related products on this page) replaces the standard collection cup and automatically shuts off the skimmer if the container fills, protecting against overflow between maintenance visits.