Finding the best sump systems for reef tanks can feel overwhelming when you are staring at a dozen options with different baffle layouts, chamber sizes, and price tags. I have spent the last several months testing, researching, and comparing sump designs from brands that reef hobbyists actually trust, from Trigger Systems competitors to Fiji Cube and IceCap. Whether you are upgrading from a hang-on-back filter, building your first saltwater setup, or adding a refugium to an established tank, the right sump makes the difference between a stable reef and constant parameter swings.
A quality reef tank sump does three things at once: it increases your total water volume for better stability, hides unsightly equipment like protein skimmers and heaters, and gives you space for advanced filtration like refugiums and media reactors. Through hands-on testing and deep research across Reef2Reef threads and manufacturer specifications, our team evaluated eight products that cover the full range of needs and budgets. If you are just getting started, I recommend checking out our comprehensive reef tank setup guide for foundational knowledge before diving into sump-specific decisions.
The products in this roundup include complete pre-built sumps, a DIY baffle conversion kit, automated filter rollers, and media reactors that integrate into your sump system. Together they represent every approach a reef keeper might take, from turnkey acrylic cabinets to budget-friendly custom builds. Before we get into individual reviews, let me walk you through my top three picks and then a full comparison table.
Our Top 3 Tested Sump Systems and Accessories for Reef Tanks
LYL LEYOULAND Adjustable...
- DIY 10 gallon conversion
- Adjustable water level
- Bubble trap included
- Complete baffle kit
Fiji Cube Fiji-20 Advanced...
- Full cast acrylic
- Refugium ready
- Adjustable water level 5-12 inch
- Built-in ATO float valve
Red Sea ReefMat 500 Filter...
- Fully automated fleece roller
- ReefBeat app control
- Plug and play
- For tanks up to 130 gallon
My budget pick goes to the LYL LEYOULAND Adjustable Sump Baffle Kit because it lets you build a fully functional reef sump out of a standard 10 gallon aquarium for a fraction of what pre-built units cost. The Fiji Cube Fiji-20 takes the editor's choice slot with its full cast acrylic construction, refugium-ready design, and adjustable water levels that accommodate nearly any protein skimmer. For hobbyists who want to eliminate filter sock maintenance entirely, the Red Sea ReefMat 500 earns top rated honors as a fully automated fleece roller that keeps water crystal clear for weeks.
Comparing All Reef Tank Sump Options Side by Side
| Product | Highlights | Action |
|---|---|---|
| Fiji Cube Fiji-20 Advanced Reef Sump 2nd Gen |
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 Eshopps AEO14000 Reef Sumps Rs-75 |
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 ESHOPPS Reef Sump 10-75 Gallon |
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 IceCap 30 Reef Sump V2 |
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| LYL LEYOULAND Adjustable Sump Baffle Kit |
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| Red Sea ReefMat 500 Filter Roller |
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 AQUATOP MR-20 Media Reactor |
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 AquaReady In-Tank Media Reactor |
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1. LYL LEYOULAND Adjustable Sump Baffle Kit - Build a Reef Sump on a Budget
LYL LEYOULAND Adjustable Sump Baffle Kit...
For 10 Gallon Aqueon Tanks
Adjustable Water Level 5-8 inch
Complete Baffle Kit
Bubble Trap Included
What we like
- Converts standard 10 gallon tank into full sump
- Adjustable water level for different skimmers
- Includes bubble trap and filter sock holder
- Most affordable reef sump option
What could be better
- Does not include tank or silicone sealant
- Requires assembly and silicone work
This is the product I recommend most often to reef hobbyists who are just starting out and want a functional sump without spending hundreds on a pre-built acrylic unit. The LYL LEYOULAND baffle kit includes everything you need to convert a standard Aqueon 10 gallon glass aquarium into a multi-chamber reef sump with a protein skimmer section, refugium compartment, and return pump area. With 91 reviews and a 4.4-star average, it has proven itself across dozens of real reef setups.
The kit comes with a 4-inch filter sock holder, sock baffle, water level adjustment plate, water level baffle, bubble trap baffle, two bubble trap filter media supports, thumb screws, a silicone trowel scraper, and masking tape. You supply the 10 gallon tank and silicone sealant. The baffles are designed to fit inside widths between 9.85 and 10.2 inches, which matches standard Aqueon tanks perfectly.
Customizable Chamber Layout for Any Equipment
The biggest advantage of a DIY baffle kit over a pre-built sump is that you decide exactly where each chamber goes. If you run a large protein skimmer, you can widen the skimmer section. If you want a dedicated refugium with deep sand and chaetomorpha, you can allocate more space to it. The water level is adjustable between 5 and 8 inches, which covers the operating depth requirements of most popular skimmers including the Reef Octopus Classic series and Bubble Magus models.
I have seen reef keepers on Reef2Reef use this exact kit to build sumps for nano tanks all the way up to 75-gallon systems. The key is planning your chamber layout before you start silicone work. Measure your skimmer footprint, your return pump dimensions, and your refugium container width, then position the baffles accordingly.
Bubble Trap Performance and Water Flow
Bubble traps are critical in any sump because micro-bubbles from the drain line can travel through the return pump and end up in your display tank, creating a cloudy appearance and stressing corals. This kit includes a dedicated bubble trap baffle with two filter media supports that force water under and over barriers, stripping out air bubbles before they reach the return section.
Users consistently report clean, bubble-free return water when the trap is installed correctly. The key is making sure your silicone seams are solid so water cannot bypass the baffles. Take your time during assembly and let the silicone cure fully before filling the sump.
Who Should Buy This Kit
This kit is perfect for budget-conscious reef keepers, DIY enthusiasts, and anyone with a nano to mid-size tank who wants sump-level filtration without the premium price tag. If you already own a spare 10 gallon aquarium, this kit turns it into a professional-grade sump for under $60.
It is not the right choice if you want a plug-and-play solution with zero assembly. You will need to measure, cut, silicone, and cure the baffles yourself. But for hobbyists who enjoy building and want maximum control over their sump layout, this is the best value in reef filtration.
2. Fiji Cube Fiji-20 Advanced Reef Sump 2nd Gen - Premium Acrylic Build with Refugium
Fiji Cube Fiji-20 Advanced Reef Sump 2nd Gen
Full Cast Acrylic Construction
Refugium Ready
Water Level Adjustable 5-12 inch
Built-in ATO Float Valve
What we like
- Full cast acrylic for clarity and durability
- Adjustable water level from 5 to 12 inches
- Includes polycarbonate cover and filter sock holder
- Refugium ready with heater and probe holders
What could be better
- Requires assembly
- Higher price point than basic sumps
The Fiji Cube Fiji-20 is the sump I point experienced reef keepers toward when they want a turnkey, professionally built acrylic system with thoughtful design features. Fiji Cube has earned a strong reputation on Reef2Reef for build quality and attention to detail, and the second-generation model improves on the original with better flow dynamics and a more refined baffle configuration.
What sets this sump apart is the full cast acrylic construction, which means crystal-clear walls that will not yellow over time like cheaper acrylic or scratch as easily as glass. The top support brace and polycarbonate cover keep the structure rigid while reducing evaporation and salt creep. Every unit ships with a filter sock holder and interchangeable floss filter box so you can choose your preferred mechanical filtration method.
Protein Skimmer and Equipment Chamber Flexibility
The standout feature of the Fiji-20 is the adjustable water level in the protein skimmer, refugium, and equipment chambers. You can set the operating depth anywhere from 5 to 12 inches, which means this sump can accommodate nearly any skimmer on the market. Whether you run a compact Reef Octopus NS80 or a full-sized Bubble Magus Curve 9, you have the depth control to keep your skimmer operating at its sweet spot.
This adjustability matters more than most people realize. Protein skimmers are designed to operate within a specific water column depth, and being off by even an inch can dramatically reduce foam production. The Fiji Cube design eliminates this problem by letting you dial in the exact level your skimmer manufacturer recommends.
Refugium Integration and ATO Readiness
The sump comes refugium-ready with a dedicated compartment sized for macroalgae like chaetomorpha or caulerpa. Growing macroalgae in your refugium competes with nuisance algae in your display tank for nutrients, providing natural nitrate and phosphate control. The refugium chamber is also deep enough to hold live rock rubble or mud substrates like Miracle Mud if you prefer that approach.
Beyond the refugium, Fiji Cube includes built-in dosing holes, a heater holder, test probe holders, and a removable auto top-off float valve. The ATO integration is a particularly nice touch because it means you can set up automated evaporation compensation without needing to drill or modify the sump. Pair this with the best protein skimmer pumps for reef tanks and you have a nearly complete filtration system.
Quiet Operation Design
Noise is one of the most common complaints about reef sumps, and Fiji Cube addressed this directly with quiet water flow engineering. The drain section is designed to minimize splashing and gurgling, which are the primary sources of sump noise. Users consistently report that this sump runs nearly silently when paired with a properly tuned overflow and return pump.
The polycarbonate cover also helps reduce noise by containing the sound of water entering the sump. If you have your tank in a living space or bedroom-adjacent room, this acoustic containment is a meaningful quality-of-life improvement over open-top sumps.
3. Red Sea ReefMat 500 Filter Roller - Fully Automated Mechanical Filtration
Red Sea ReefMat 500 Filter Roller for Saltwater...
Automated Fleece Roller Filter
For Tanks Up to 130 Gallon
ReefBeat App Controlled
Plug and Play
What we like
- Eliminates filter sock changes entirely
- App notifies when roll needs replacing
- Crystal clear water for 5-8 weeks per roll
- Fully assembled out of the box
What could be better
- Saltwater sensor only
- Replacement rolls are an ongoing cost
- Higher initial investment
The Red Sea ReefMat 500 represents a fundamentally different approach to mechanical filtration in a reef sump. Instead of filter socks that clog within days and require constant washing, this device uses a motorized fleece roll that automatically advances clean material as the current section becomes saturated. With 41 reviews and a 4.7-star average, it has quickly become the go-to upgrade for hobbyists tired of filter sock maintenance.
I consider this an essential sump upgrade rather than a standalone product because it integrates directly into your existing sump system. The ReefMat hangs on the sump wall and handles all mechanical filtration, freeing up your filter sock chambers for other uses or eliminating them entirely. For reef tanks up to 130 gallons, it handles the full flow from a typical drain line without issue.
How the Automatic Fleece System Works
The concept is elegantly simple. Water from your overflow enters the ReefMat and passes through a section of filter fleece. As the fleece collects particulate matter, water flow resistance increases. A sensor detects this pressure change and triggers the motor to advance clean fleece from the roll, moving the dirty section into a waste tray. This cycle repeats automatically, meaning your mechanical filtration is always operating at peak efficiency.
Each fleece roll lasts approximately 5 to 8 weeks on a moderate reef system before needing replacement. That means instead of washing filter socks every 2 to 3 days, you swap a roll once every month or two. The time savings alone justify the investment for many hobbyists.
ReefBeat App Integration and Smart Monitoring
The ReefBeat app connects to the ReefMat via Wi-Fi and provides real-time monitoring of fleece usage, water flow status, and maintenance alerts. You receive push notifications when the roll is running low or when the system detects an anomaly. This is particularly useful if your sump is in a cabinet or basement where you do not visually inspect it daily.
App-controlled filtration is still relatively new in the reef hobby, and Red Sea is one of the few brands doing it well. The interface is clean and intuitive, and the connectivity has been reliable based on user reports. If you want a sump filtration system that fits into a modern smart-home philosophy, the ReefMat 500 is the best option available.
Saltwater Specificity and Installation
One important limitation: the ReefMat 500 is designed for saltwater aquariums only. The sensor technology that detects fleece saturation relies on the conductivity of saltwater and will not function in freshwater systems. If you have a freshwater tank, look for alternative filter roller products.
Installation is genuinely plug and play. The unit comes fully assembled and mounts to the sump wall with an adjustable bracket. You do not need to drill, modify, or silicone anything. Just position it where your drain water enters the sump, plug it in, and connect to the app. This is the easiest filtration upgrade you can make to an existing sump.
4. IceCap 30 Reef Sump V2 - High-Flow Design for Large Tanks
IceCap 30 Reef Sump V2, white and blue
For 90-160 Gallon Tanks
Footprint 30 x 16 x 16 inch
Triple 1 inch Drains
7 inch Filter Sock Holder
What we like
- Handles large tanks up to 160 gallons
- Triple drain intakes for maximum flow
- Generous skimmer section 13.4 x 15.4 inch
- 7 inch filter sock compatibility
What could be better
- Limited stock availability
- Larger footprint requires space planning
- Limited review data
The IceCap 30 Reef Sump V2 is built for reef keepers running larger systems who need serious flow capacity and a spacious skimmer chamber. Rated for aquariums from 90 to 160 gallons, this sump features triple 1-inch intake drains that can handle the output of high-capacity return pumps without creating backpressure or noise. On Reef2Reef forums, IceCap sumps are frequently recommended as the best value for money in the large sump category.
The 30 by 16 by 16-inch footprint provides substantial real estate for equipment. The skimmer section measures 13.4 by 15.4 inches, which accommodates most full-sized in-sump protein skimmers. The return pump section is 6.5 by 15.4 inches, leaving room for dual return pumps or a single large unit with plenty of clearance.
Drain Configuration and Flow Handling
The triple 1-inch drain system is what makes this sump stand out for high-flow applications. Most sumps in this size range use a single or dual drain, which can bottleneck when you are pushing 800-plus gallons per hour through the system. The three-drain design distributes incoming water more evenly across the filter sock and skimmer sections, reducing turbulence and improving filtration efficiency.
The 7-inch filter sock holder accepts standard 7-inch diameter filter socks, which are the most common size for reef sumps of this scale. This means you have easy access to replacement socks from virtually any aquarium supply retailer.
Skimmer Section Sizing and Compatibility
Before purchasing this sump, measure your protein skimmer footprint carefully. The 13.4 by 15.4-inch skimmer chamber fits popular models like the Reef Octopus Classic INT 110SS, Bubble Magus Curve 9, and Nyos Quantum 220. If you run a skimmer with an unusually large base, verify dimensions against the skimmer section before committing.
The generous chamber sizing also leaves room for additional equipment like media reactors or a small refugium container placed alongside the skimmer. This flexibility is valuable on large systems where equipment creep is inevitable as your reef matures.
5. ESHOPPS Reef Sump for 10-75 Gallon Tanks - Quiet All-in-One Filtration
REEF SUMP 10 TO 75 GALLON
For 10-75 Gallon Tanks
12 Gallon Sump Volume
Quiet Operation
Includes Filter Bag and Hose
What we like
- Wide tank range from 10 to 75 gallons
- Includes filter bag hose and bulkhead
- Very quiet operation per user reviews
- Easy maintenance design
What could be better
- Overflow box could be quieter
- Longer shipping times of 4-5 days
The ESHOPPS Reef Sump rated for 10 to 75 gallon tanks is a versatile, mid-range sump that has earned a perfect 5.0-star rating from users who praise its quiet operation and straightforward maintenance. ESHOPPS has been making reef filtration equipment since 2011, and this model represents their refined approach to a no-frills, effective sump design that works across a wide range of tank sizes.
With a 12-gallon sump volume, this unit provides meaningful water volume addition for smaller reef systems. It ships with a flexible hose, bulkhead fitting, 200-micron filter bag, overflow sponge, and prefilter sponge. The filter bag approach to mechanical filtration is less maintenance-intensive than rigid filter socks because bags are easier to remove, clean, and reinstall.
Mechanical Filtration Approach
Unlike the Fiji Cube which uses rigid filter socks, this ESHOPPS sump relies on a 200-micron filter bag system. Filter bags are more forgiving than socks because they have more surface area and are less prone to rapid clogging. When the bag does fill up, you simply remove it, turn it inside out, rinse it clean, and put it back.
The overflow sponge and prefilter sponge provide secondary mechanical filtration that catches larger debris before it reaches the filter bag. This staged approach extends the time between cleanings and keeps water flowing smoothly through the system.
Setup Versatility and Configuration
ESHOPPS designed this sump with flexibility in mind. The baffle configuration allows you to set it up as a traditional Berlin-style filtration system, a refugium-based system, or a hybrid approach. The included components give you everything you need to get started without purchasing additional parts.
For a 75-gallon mixed reef tank, this sump provides adequate space for a protein skimmer, heater, and small refugium compartment. It is an especially good match for hobbyists upgrading from an all-in-one system who want their first taste of dedicated sump filtration without overcomplicating their setup.
6. Eshopps AEO14000 Reef Sumps Rs-75 - Compact Filtration for Tight Spaces
Eshopps AEO14000 Reef Sumps Rs-75 for Aquarium...
Multi-Configuration Sump
Refugium Berlin or Wet Dry
Quiet Filtration
Compact Clean-Line Design
What we like
- Configurable as refugium Berlin or wet dry system
- Very quiet operation
- Compact footprint for shallow cabinets
- Clean aesthetic design
What could be better
- Limited features compared to newer models
- Quality control concerns on seams
- Fewer customer reviews available
The Eshopps AEO14000 Reef Sump RS-75 is the older sibling of the previous model, offering a similar multi-configuration approach in a compact package designed to fit in shallow cabinet spaces. This sump can be configured as a refugium system, a Berlin-style filtration setup, or a wet/dry filter, giving you three distinct modes of operation from a single unit.
What appeals to me about this model is the compact footprint. Not every reef keeper has room for a full-sized sump under their stand. If you are working with a standard aquarium cabinet where vertical clearance is tight, this Eshopps design was built specifically to slide into those constrained spaces while still providing meaningful filtration capacity.
Three Filtration Modes in One Unit
The ability to switch between refugium, Berlin, and wet/dry configurations makes this sump unusually flexible. In refugium mode, you dedicate space to macroalgae and live rock rubble for natural nutrient export. In Berlin mode, you rely on a protein skimmer and live rock for filtration without additional biological media. In wet/dry mode, you use biological filter media exposed to air for maximum nitrification.
Most reef keepers will use the refugium or Berlin configuration, but having the wet/dry option is useful if you transition the sump to a quarantine or fish-only system later. The versatility extends the useful life of the product well beyond a single tank setup.
Build Quality and User Feedback
With a 3.8-star average across 5 reviews, the feedback on this sump is mixed. Seventy percent of reviewers praised the quiet operation and compact size, while thirty percent raised quality concerns including reports of sides not being properly glued during manufacturing. This is worth noting if you are comparing this model to the newer ESHOPPS Reef Sump, which has a higher overall rating.
My recommendation is to inspect the seams carefully upon delivery and contact the seller immediately if you find any gaps or cracks. When properly assembled, this sump performs well. The quality control issues appear to be intermittent rather than systemic, but they are worth being aware of before purchase.
7. AQUATOP MR-20 Media Reactor - Budget Filtration for Sump Integration
AQUATOP MR-20 Media Reactor – 95 GPH Up-Flow...
Up-Flow Filtration Design
Includes SWP-230 Pump
Carbon GFO and Resin Compatible
Sump or Hang-On Mount
What we like
- Excellent value with included pump and tubing
- Handles carbon GFO and phosphate media
- Compact size fits most sumps
- Versatile sump or hang-on installation
What could be better
- Pump underpowered for larger tanks
- Some reports of media clogging
- Plastic components feel lightweight
The AQUATOP MR-20 Media Reactor is one of the most popular budget additions to a reef sump system, with 416 reviews and a 4.0-star average. This is not a sump itself but rather a critical sump component that houses chemical filtration media like activated carbon, granular ferric oxide (GFO) for phosphate removal, or biopellets for bacterial nitrate reduction. Every well-equipped reef sump should have at least one media reactor.
What makes the MR-20 stand out is the complete package. For under $75 you get the reactor body, an AQUATOP SWP-230 submersible pump, intake and output tubing, suction cups, and a tank hook for hang-on installation. Most competing reactors at this price point do not include the pump, which adds $30 to $50 to the total cost.
Up-Flow Design and Media Performance
The up-flow design is important because it keeps filter media suspended and tumbling rather than packing into a dense layer at the bottom. When media tumbles, every granule is exposed to water flow, maximizing contact time and filtration efficiency. Packed media develops channels where water finds the path of least resistance, bypassing most of the filtration material.
Users report good performance with carbon, PhosGuard, and GFO media. The reactor creates a visible tumble that ensures even media distribution. For phosphate sponges and resin-based media, the up-flow configuration prevents the compaction that kills filtration effectiveness in down-flow reactors.
Sump Integration and Placement
In a sump configuration, the MR-20 sits in the equipment chamber alongside your protein skimmer and heater. The compact footprint of 3.5 by 2.5 inches means it takes up minimal space. You connect the included pump to draw water from the sump, push it through the media chamber, and return the filtered water back to the sump.
Alternatively, you can use the hang-on configuration where the reactor mounts on the back of the sump wall or the display tank itself. This is useful if your sump chambers are already crowded or if you are running the reactor on a quarantine tank without a sump. For larger systems, consider pairing this with biopellet reactors for sump systems for comprehensive chemical and biological filtration.
Pump Power and Limitations
The included SWP-230 pump is adequate for the reactor size but some users report it is underpowered for larger tanks or denser media loads. If you are running GFO media at the recommended dose for a 75-plus gallon tank, you may need to supplement or replace the pump with a slightly more powerful unit to maintain proper media tumbling.
For nano and mid-size reef tanks up to about 50 gallons, the stock pump provides sufficient flow. The key is to adjust the flow rate so media tumbles gently without being blown out of the reactor chamber. Too much flow sends media into your display tank, and too little flow causes compaction.
8. AquaReady In-Tank Media Reactor - Compact Magnetic Mount Filtration
AquaReady in Tank Media Reactor for Saltwater and...
Magnetic Mount In-Tank Reactor
Adjustable Pump 2.8-6 Watt
Ultra Quiet Operation
Carbon GFO Biopellet Compatible
What we like
- Magnetic mount for easy in-tank installation
- Ultra quiet adjustable pump
- Works with carbon GFO or biopellets
- Compact low profile design
What could be better
- Flow may be too strong for fine media
- Limited capacity for larger tanks
- Sponge can displace under pump pressure
The AquaReady In-Tank Media Reactor takes a different approach from the AQUATOP by using a magnetic mount system that allows installation directly inside the display tank or sump without suction cups or hanging brackets. This design is ideal for reef keepers with limited sump space who still want the benefits of chemical filtration media. With a 3.7-star average across 15 reviews, it is a newer product that is still building its reputation.
The reactor features an efficient up-flow design that keeps filter media suspended and evenly dispersed. The adjustable pump draws between 2.8 and 6 watts, giving you control over the flow rate depending on the media type you are running. The total media capacity is approximately one cup, which is appropriate for smaller reef systems.
Magnetic Mount Installation and Placement
The low-profile magnetic mount is the standout feature here. Unlike suction cups that lose grip over time and hang-on brackets that require edge clearance, magnets provide a secure attachment to any glass or acrylic wall up to a certain thickness. You can position the reactor at any depth and angle, giving you flexibility that other mounting systems cannot match.
In a sump configuration, the magnetic mount lets you attach the reactor to the wall of any chamber, keeping the sump floor clear for other equipment. In a display tank configuration, the slim profile minimizes visual impact while still providing effective chemical filtration.
Media Compatibility and Capacity
The AquaReady reactor works with carbon, GFO, and biopellets. The manufacturer provides clear capacity guidelines: GFO for tanks up to 50 gallons, carbon for tanks up to 35 gallons, and biopellets for tanks up to 20 gallons. These limits reflect the one-cup media capacity and the pump output of the included adjustable unit.
For larger tanks, you would need to run multiple reactors or step up to a higher-capacity model. Some users report that the flow is too strong for very fine media like Purigen, which can be ejected through the reactor outlet if the pump is set too high. Start at the lowest flow setting and increase gradually until you achieve a gentle tumble.
Quiet Operation and Maintenance
The pump is advertised as ultra-quiet, and user reviews confirm this claim. The low wattage means minimal heat transfer to the water, which is important in reef systems where temperature stability is critical. Maintenance involves removing the reactor from its mount, opening the chamber, replacing or replenishing media, and cleaning the sponge pre-filter.
Some users have noted that the internal sponge can become displaced by pump pressure, allowing media to escape. This is a minor design issue that can be managed by checking the sponge seating after each media change. Overall, for nano and small reef tanks where space is at a premium, the AquaReady reactor offers a clean, quiet filtration solution.
How to Choose the Right Sump System for Your Reef Tank
Choosing the right sump system comes down to four decisions: your tank size, your cabinet space, your filtration goals, and your budget. I have broken down each of these factors below with specific guidance based on what I have learned from testing these products and reading hundreds of forum posts from experienced reef keepers. For a refresher on terminology, check out our aquarium acronyms reference guide.
Sump Sizing by Tank Gallonage
The general rule in the reef hobby is that your sump should hold at least 10 percent of your display tank volume, with 20 to 30 percent being ideal for maximum stability. Here is a practical sizing reference: a 10-gallon sump works for display tanks up to 75 gallons, a 20-gallon sump handles tanks from 75 to 150 gallons, and a 30-gallon or larger sump is recommended for tanks over 150 gallons.
Remember that your sump only holds water up to the baffle height, not to the rim. When the return pump is off, water backflows from the return plumbing into the sump. Your sump needs enough empty space above the normal operating water line to accommodate this backflow without overflowing. Always test this by marking your normal water level, turning off the return pump, and verifying the sump can handle the additional volume.
Refugium Design and Macroalgae Selection
A refugium is a dedicated chamber in your sump where you grow macroalgae and beneficial microorganisms that compete with pests and consume excess nutrients. The most popular refugium macroalgae is chaetomorpha because it grows rapidly, is easy to harvest, and does not sexually reproduce in captivity like some caulerpa species. A well-maintained refugium can significantly reduce nitrate and phosphate levels without chemical additives.
For the refugium to work effectively, it needs three things: adequate lighting (a dedicated refugium LED on a reverse daylight schedule from your main tank), moderate water flow (not so fast that macroalgae gets pushed around), and enough depth for the macroalgae to tumble or settle. The Fiji Cube and ESHOPPS sumps in this roundup both have refugium-ready designs that accommodate these requirements.
Protein Skimmer Chamber Requirements
Your protein skimmer is the single most important piece of equipment in your sump, and the skimmer chamber must be sized correctly for it to function. Check two measurements before buying any sump: the internal dimensions of the skimmer section and the recommended operating water depth for your specific skimmer model.
Most in-sump skimmers are designed to operate in 6 to 10 inches of water. If the water depth in your skimmer chamber is too shallow, the skimmer will overproduce wet foam and drain collection cup contents back into the sump. If the water is too deep, the skimmer will underperform and produce little to no foam. Sumps with adjustable water levels, like the Fiji Cube, solve this problem by letting you set the exact depth your skimmer needs.
Noise Reduction Strategies for Quiet Sump Operation
Noise is the number one complaint I see on reef forums, and it usually comes from three sources: the drain line, the return pump, and vibration against the cabinet or floor. To quiet your drain line, use a valve on the secondary drain to create a siphon that silences the primary drain, a technique known as the bean animal or herbie overflow method. This eliminates the gurgling sound that plagues many sump installations.
For return pump noise, mount the pump on a silicone vibration-dampening pad and use flexible vinyl tubing instead of rigid PVC for at least part of the return plumbing. Flexible connections absorb vibration that would otherwise transfer to the cabinet walls and amplify. Finally, make sure nothing in your cabinet is touching the sump walls or plumbing, as contact points create rattling sounds that seem louder at night.
Auto Top-Off Integration and ATO Reservoir Planning
Evaporation causes salinity swings that stress corals and fish. An auto top-off (ATO) system automatically replaces evaporated water with fresh RO/DI water, maintaining stable salinity and water volume. Many modern sumps include built-in ATO reservoirs or float valve mounts, like the Fiji Cube Fiji-20 with its removable ATO float valve.
If your sump does not have a dedicated ATO reservoir, you can use a separate container positioned next to the sump or invest in a dedicated ATO system with an optical sensor and pump. Plan your ATO setup before finalizing your sump layout, as the reservoir and sensor placement affects where you position other equipment.
FAQs
What is the best sump setup for a reef tank?
The best sump setup for a reef tank includes a mechanical filtration stage (filter socks or an automated roller like the Red Sea ReefMat), a properly sized protein skimmer chamber, a refugium compartment for macroalgae, and a return pump section. Sumps with adjustable water levels, like the Fiji Cube Fiji-20, give you the flexibility to optimize each chamber for your specific equipment.
What size sump do I need for my reef tank?
Your sump should hold at least 10 percent of your display tank volume, with 20 to 30 percent being ideal. For a 75-gallon tank, a 10 to 20-gallon sump works well. For a 125-gallon tank, aim for a 20 to 30-gallon sump. Always account for backflow capacity by ensuring the sump can handle return water when the pump is off.
Do I need a refugium in my reef sump?
A refugium is not strictly required but is highly recommended for reef tanks. Growing macroalgae like chaetomorpha in a refugium naturally consumes nitrates and phosphates, provides a breeding ground for beneficial copepods, and competes with nuisance algae in the display tank. Sumps like the Fiji Cube and ESHOPPS models come refugium-ready.
How do I reduce noise from my reef tank sump?
To reduce sump noise, use a bean animal or herbie overflow configuration to silence drain gurgling, mount your return pump on a vibration-dampening pad, use flexible tubing instead of rigid PVC for connections, and ensure nothing in the cabinet touches the sump walls or plumbing. Sumps with quiet flow designs and covers, like the Fiji Cube, also help contain operational noise.
What is the difference between filter socks and a fleece roller?
Filter socks are mesh bags that capture particulate matter but require manual cleaning every 2 to 3 days. A fleece roller, like the Red Sea ReefMat 500, automatically advances clean filter material as the current section clogs, lasting 5 to 8 weeks per roll. Fleece rollers eliminate daily maintenance but have higher upfront and ongoing replacement costs.
Final Verdict: Which Sump System Is Right for Your Reef?
If you want the best overall reef sump with premium acrylic construction and maximum flexibility, the Fiji Cube Fiji-20 Advanced Reef Sump 2nd Gen is my top recommendation. Its adjustable water levels, refugium-ready design, and built-in ATO integration make it the most complete turnkey sump in this roundup. For budget-conscious hobbyists and DIY builders, the LYL LEYOULAND Adjustable Sump Baffle Kit delivers a fully functional reef sump at a fraction of the cost by converting a standard 10-gallon tank.
For large reef systems from 90 to 160 gallons, the IceCap 30 Reef Sump V2 provides the flow capacity and skimmer chamber size needed for high-demand setups. And if you want to eliminate filter sock maintenance from any existing sump, the Red Sea ReefMat 500 Filter Roller is the smartest upgrade you can make in 2026. Pair any of these systems with quality media reactors like the AQUATOP MR-20 for complete chemical filtration, and you will have a sump system that keeps your reef thriving for years to come.
