Reef Octopus OCTO Reef Sump | Premium Acrylic Reef Sump with Built-In ATO Reservoir | 15A, 24A, 30A & 36A

Create the foundation for a healthier, cleaner, and more organized reef aquarium with the Reef Octopus OCTO Reef Sump. Designed with both beginner and advanced reef keepers in mind, the OCTO Series combines premium acrylic construction, intelligent chamber layouts, adjustable water levels, and an integrated freshwater ATO reservoir into one beautifully engineered filtration system.

Available in four sizes, the OCTO Reef Sump allows you to choose the perfect model for your aquarium while providing ample room for protein skimmers, return pumps, heaters, probes, media reactors, and future upgrades.

Whether you're building your first reef aquarium or upgrading an existing system, the OCTO Series delivers the quality, reliability, and thoughtful design Reef Octopus is known for.

Key Features

• Premium cell-cast acrylic construction

• Four sizes available to fit a wide range of aquariums

• Integrated freshwater ATO reservoir

• Adjustable skimmer chamber water depth (5.1"–9")

• Quiet bubble-diffusing intake chamber

• Filter sock holder compatible with fleece filter upgrades

• Probe holders for aquarium controllers

• Spacious equipment chambers

• Modern red and black Reef Octopus styling

• Designed for long-term reef aquarium performance

Choose the Right Size

OCTO 15A

Recommended Display Aquarium

• Up to 65 Gallons

Sump Dimensions

• 14.96" L × 14.96" W × 13.78" H

Freshwater ATO Reservoir

• 1.5 Gallons

Perfect For

• Nano reefs

• Cube aquariums

• Small mixed reefs

• Compact cabinet installations

Recommended Return Pump

• Reef Octopus VarioS-2 Controllable DC Return Pump

OCTO 24A

Recommended Display Aquarium

• 65–100 Gallons

Sump Dimensions

• 23.62" L × 14.17" W × 15.75" H

Freshwater ATO Reservoir

• 3 Gallons

Perfect For

• Medium reef aquariums

• Mixed reefs

• LPS systems

• Fish-only marine aquariums

Recommended Return Pump

• Reef Octopus VarioS-2 or VarioS-4 Controllable DC Return Pump

OCTO 30A

Recommended Display Aquarium

• 100–150 Gallons

Sump Dimensions

• 29.92" L × 15.75" W × 15.75" H

Freshwater ATO Reservoir

• 4.7 Gallons

Perfect For

• Larger mixed reefs

• SPS systems

• Heavy filtration setups

Recommended Return Pump

• Reef Octopus VarioS-4 Controllable DC Return Pump

OCTO 36A

Recommended Display Aquarium

• 150–220+ Gallons

Sump Dimensions

• 35.83" L × 18.11" W × 15.75" H

Freshwater ATO Reservoir

• 6.6 Gallons

Perfect For

• Large reef aquariums

• SPS-dominated systems

• Advanced filtration systems

• Future equipment expansion

Recommended Return Pump

• Reef Octopus VarioS-4 or VarioS-6 Controllable DC Return Pump

Why Add a Sump?

A sump is one of the best investments you can make for a saltwater aquarium. Instead of placing equipment inside your display tank, a sump moves your filtration below the aquarium, creating a cleaner appearance while improving water quality and increasing total system volume.

Benefits of a Reef Sump

Increases total water volume for greater stability

Keeps heaters, probes, skimmers, and pumps out of the display

Improves oxygen exchange

Reduces equipment clutter

Makes maintenance easier

Provides room for future upgrades

Helps create a cleaner, more professional-looking aquarium

Whether you're keeping fish, corals, or a mixed reef, a sump makes maintaining stable water conditions easier.

Designed for Today's Reef Equipment

Every OCTO Reef Sump is engineered to accommodate today's most popular aquarium equipment, including:

• Protein Skimmers

• Controllable DC Return Pumps

• Aquarium Heaters

• Media Reactors

• Aquarium Controllers

• pH, Salinity, ORP and Temperature Probes

• Auto Top-Off Systems

• Filter Socks

• Klir Roller Filter Upgrades

• Refugiums (model dependent)

Pair It with a Reef Octopus VarioS Return Pump

Complete your filtration system with a Reef Octopus VarioS Controllable DC Return Pump.

VarioS pumps provide:

• Fully controllable flow adjustment

• Quiet DC operation

• Energy-efficient performance

• Feed mode for maintenance

• Soft-start technology

• Reliable long-term operation

• Perfect compatibility with OCTO Reef Sumps

Together, the OCTO Reef Sump and VarioS Return Pump create a powerful and efficient filtration system for virtually any reef aquarium.

Why Choose Reef Octopus?

For years, Reef Octopus has been trusted by reef hobbyists around the world for producing reliable, innovative, and high-performance aquarium filtration equipment. Every OCTO Reef Sump is designed to maximize filtration efficiency while making routine maintenance easier and keeping your aquarium cabinet clean and organized.

Why Buy From Infinity and Beyond Aquatics?

When you shop with us, you're supporting a fellow aquarium hobbyist who understands what it takes to build and maintain a thriving aquatic ecosystem.

We provide:

• Authorized dealer products

• Competitive everyday pricing

• Responsive customer support

• Expert guidance before and after your purchase

• Carefully packaged orders

• Passionate service from hobbyists who genuinely love the aquarium community

Whether you're building your first reef aquarium or your dream display, we're here to help every step of the way.

Shipping Disclosure

This item ships using our Medium Shipping service and may ship directly from one of our trusted authorized distributor partners to reduce transit time and help ensure safe delivery. Regardless of where your order ships from, you'll receive the same dedicated customer service and support from Infinity and Beyond Aquatics from purchase through delivery.

Invest in the heart of your filtration system with the Reef Octopus OCTO Reef Sump and enjoy premium craftsmanship, exceptional organization, and dependable performance for years to come.