Sump Setups For Reef Tanks

Sump Setups For Reef Tanks

A well-designed sump is one of the best upgrades you can make to any reef tank. It hides equipment, increases water volume, and stabilizes parameters so your corals thrive. Whether you’re planning your first saltwater system or upgrading an existing one, choosing the right sump layout makes daily maintenance far easier.

Key Goals Of A Reef Sump

Before picking a specific setup, it helps to understand what your sump should do for your reef:

• Increase water volume for better stability and dilution of nutrients.
• Provide a place for equipment like your protein skimmer, heater, probes, and reactors.
• Improve filtration with mechanical, biological, and optionally refugium-based nutrient export.
• Allow safe top-off and dosing away from the display tank.

If you’re still planning your overall system, you may also want to read our guide on choosing the right reef tank size so your sump and display are matched from day one.

Classic 3‑Chamber Sump Layout

The most popular and beginner-friendly sump is the 3-chamber layout. It’s simple, efficient, and works for most reef tanks from nano to large systems.

Chamber 1: Drain & Mechanical Filtration

Water from the display tank overflows into the first chamber. Here you typically place:

• Filter socks or filter cups with floss
• A protein skimmer sized for your tank
• Heaters and temperature probes

Tip: Use a filter sock holder that’s easy to remove so you can swap socks every 2–3 days. This small habit dramatically improves water clarity and nutrient control.

Chamber 2: Refugium Or Equipment Zone

The middle chamber can be configured either as a refugium or an equipment zone depending on your goals:

• Refugium style: Add live rock rubble and macroalgae (like chaeto) with a dedicated refugium light. This helps export nitrate and phosphate naturally and provides a safe spot for copepods.
• Equipment style: Use this area for media reactors, additional biological media, or a roller mat if you want lower-maintenance mechanical filtration.

If you’re focused on nutrient control, pairing this chamber with the practices in our how to reduce nitrates in a reef tank article can give you a very stable, low-nutrient system.

Chamber 3: Return Section

The final chamber houses the return pump and is where your auto top-off (ATO) sensor should live. Because evaporation shows up here, you want:

• Enough volume that a little evaporation doesn’t expose your pump
• A reliable ATO system to keep salinity stable
• Space for dosing lines to drip into a high-flow area

Pro tip: Mark a “max water level” line in the return chamber. When the system is off, never fill past this line, or you risk an overflow when power returns.

Advanced Options: Roller Mats & Manifolds

For larger or heavily stocked reef tanks, you can enhance a standard 3-chamber sump with a few upgrades:

• Roller mat mechanical filters that automatically advance as they clog, cutting down on filter sock changes.
• Plumbed manifolds off the return line to feed media reactors, UV sterilizers, or algae scrubbers without extra pumps.
• Oversized skimmers to handle higher bioloads and heavy feeding schedules.

These features add cost, but they dramatically reduce hands-on maintenance and keep water quality more consistent—especially helpful if you’re running demanding SPS corals.

Putting It All Together

The best sump setup for your reef tank is the one that matches your goals, budget, and maintenance style. For most hobbyists, a simple 3-chamber sump with a skimmer, refugium, and well-sized return section offers the ideal balance of performance and simplicity. As your reef grows, you can always upgrade components or add reactors and roller mats to the same basic layout.

Design your sump with access and maintenance in mind from the start, and you’ll spend less time fighting equipment and more time enjoying your corals. For more planning help, check out our overview of essential reef tank equipment to be sure your sump supports everything your system needs.

Sources

• Sprung, J. & Delbeek, J. C. The Reef Aquarium, Vol. 1–3. Ricordea Publishing.
• Feldman, K. M. et al. “Nutrient dynamics in reef aquaria.” Advanced Aquarist archives.
• Manufacturer documentation from major sump and skimmer brands (Trigger Systems, Bashsea, Royal Exclusiv).