Top 10 Aquarium Sumps for Custom Reef Aquariums in 2027

1. Trigger Systems Ruby 36e

This sump ranks first because it pairs the widest feature set with the highest tested flow on the list. The 36" x 18" x 16" cast acrylic body holds 36 gallons total, including a 7-gallon refugium, and its dual-weir baffle stack handles up to 1,500 GPH without pushing micro-bubbles into the display. A 4-sock holder, a 4-probe holder, a media rack, and a dedicated UV sterilizer return port all come included at $1,099.

Buy it for a 75-120 gallon SPS build where chaeto or mangroves need real refugium volume and probes need a permanent home. What you trade is money: $250 more than the CL-36 below it, and acrylic that scratches under careless cleaning. The compensation is fewer external reactors hanging off the stand, since the UV port and media rack absorb work a separate canister would otherwise do.

2. Alignment Reef Systems CL-36

Second place is earned on price-to-feature ratio: $849 buys a 36" x 16" x 16" glass sump with a 30-gallon volume and a 10-gallon refugium, three gallons larger than the $1,099 Ruby 36e's. The 3/8" glass panels are joined with silicone seams rated for saltwater, and the bubble-trap baffle section is tuned for 1,200 GPH. A 3-sock holder is included, plus a carbon reactor chamber sized for a BRS GFO reactor.

This suits 60-90 gallon tanks run by builders who would rather spend the saved $250 on a skimmer or return pump. The trade is weight and flow ceiling: glass pushes the loaded sump past 40 lbs, so the stand has to be checked, and 1,200 GPH caps you below the Ruby 36e's 1,500. Probe holders accept Apex probes, so controller integration is not the compromise.

3. Fiji Cube 36-Inch Sump

Third place goes to the largest refugium on any acrylic sump here: 10 gallons inside a 36" x 18" x 16" shell with 35 gallons total volume, at $999. The dual-overflow weir design is built for quiet operation and carries 1,400 GPH, within 100 GPH of the top pick. A 4-sock holder, a media basket for carbon or GFO, and a UV sterilizer port are all included in that price.

This is the pick for 75-100 gallon SPS systems where nutrient export through macroalgae is the primary strategy. It gives up the Ruby 36e's 4-probe holder and 100 GPH of flow while saving $100. Acrylic keeps it lighter than the glass CL-36 above, but it scratches easily enough that a mag-float rather than a scraper should be the cleaning tool.

4. Eshopps R-300 Refugium Sump

Fourth reflects a deliberate size-and-price break: $499 for a 30" x 12" x 16" acrylic sump with 30 gallons of volume, roughly half the cost of the 36-inch models above it. The narrow 12" width lets it slide under standard 48" stands that will not clear an 18" deep sump. Flow tops out at 1,000 GPH, and the box includes a 5-gallon refugium, a media rack for carbon, and a 2-sock holder.

Aim this at 40-60 gallon custom builds paired with a compact skimmer like the Tunze DOC 9004. The clear trade is mechanical filtration capacity: two socks instead of the four on the Fiji Cube above, which becomes a real constraint on heavy bioloads or fish-dense systems. The 5-gallon refugium grows chaeto fine but will not support the mangrove setups the larger sumps handle.

5. Reef Octopus VarioS Sump 36

Fifth place is a value judgment, not a build-quality one: at $1,199 this is the most expensive sump on the list, though a DC-controlled VarioS return pump rated at 1,200 GPH is included in that number. The 36" x 18" x 16" acrylic body holds 35 gallons with an 8-gallon refugium behind a mesh divider, plus a 4-sock holder and a 3-probe holder.

This fits 90-120 gallon builds where a factory-matched pump is worth more than a la carte flexibility, since the DC controller trims energy draw. Against the Ruby 36e it costs $100 more, holds a gallon less, and moves 300 GPH less water, and it has no UV port. The included pump is what closes that gap for anyone who has not already bought one.

6. Trigger Systems Sapphire 26

Sixth position comes from footprint rather than feature count: a 26" x 18" x 16" acrylic sump holding 26 gallons, priced at $799. Despite the shorter body it still carries 1,200 GPH, matching sumps a foot longer, and includes a 5-gallon refugium, a 3-sock holder, a media rack, and a probe holder. The baffle work is the same Trigger Systems design used in the Ruby line.

This is for 50-75 gallon tanks where the stand opening, doors, or plumbing runs rule out a 36" sump. Compared with the Ruby 36e it surrenders 10 gallons of volume, two gallons of refugium, 300 GPH, and the UV port for a $300 saving. Against the cheaper Eshopps R-300 it adds a sock, a probe holder, and 200 GPH.

7. Fiji Cube 30-Inch Sump

Seventh is the middle of the size ladder: 30" x 16" x 16" acrylic, 30 gallons total, $799. Flow capacity is 1,200 GPH, equal to the Sapphire 26 at the same price, and the 6-gallon refugium is a gallon larger. Included hardware covers a 3-sock holder and a media basket; the UV port is optional rather than standard as it is on the 36-inch Fiji Cube.

This lands well for 60-80 gallon systems, particularly for reefers stepping up from a 20-gallon starter sump who want refugium space without a 36" footprint. Versus the Sapphire 26 above it trades a probe holder for four extra inches of length and a larger refugium. Versus the $999 36-inch Fiji Cube it gives up four gallons of macroalgae space and a sock.

8. Alignment Reef Systems CL-24

Eighth place is set by capacity: 24" x 16" x 16" glass, 24 gallons total, $699. Flow is rated at 1,000 GPH, and the 6-gallon refugium is unusually generous for the overall volume — a quarter of the sump given over to macroalgae. A carbon reactor chamber is built in, which removes a separate canister from the stand, and a 2-sock holder handles mechanical filtration.

This fits 40-60 gallon builds on 36" stands where nothing longer will physically go. The glass construction is scratch-resistant and durable but pushes 35 lbs empty, so stand load matters more than with the acrylic picks. Against the CL-36 it keeps the carbon chamber and loses six gallons of volume, four gallons of refugium, a sock, and 200 GPH for $150.

9. Eshopps R-200 Refugium Sump

Ninth is the smallest and cheapest entry: 24" x 12" x 16" acrylic, 20 gallons of volume, $399. That is $100 less than the R-300 and $700 below the Ruby 36e. The tradeoff shows in throughput — 800 GPH is the lowest ceiling on this list — and in a 4-gallon refugium plus a 2-sock holder. A media rack for carbon is included at that price.

This works for nano and small custom builds in the 30-50 gallon range on 30" stands. The 800 GPH limit is the real constraint: a return pump sized for a larger display will overwhelm the baffles, so pump selection has to be deliberate. Compared with the CL-24 above it saves $300 and roughly 20 lbs, giving up two gallons of refugium and 200 GPH.

10. Trigger Systems Crystal 36

Tenth despite strong specs, because the $50 saved against the Ruby 36e costs a feature that matters. The 36" x 18" x 16" acrylic body matches the Ruby exactly at 36 gallons with a 7-gallon refugium, 1,500 GPH capacity, a 4-sock holder, a media rack, and a probe holder, at $1,049. What it does not have is the UV sterilizer return port, which pushes UV back to external plumbing.

The reason to choose it is the transparent Crystal-line construction, which makes water levels and chamber conditions readable at a glance in a 75-120 gallon build. That clarity is also its weakness: the panels scratch more readily than the Ruby series, so cleaning discipline matters. For anyone not running UV, it is the same sump for $50 less than the top pick.

How we ranked these

We weighed five things: build quality (acrylic vs. glass, panel thickness, seam integrity), flow capacity and baffle behavior at rated GPH, customization hooks like sock holders, media racks and probe mounts, footprint fit under standard 40–120 gallon stands, and price relative to included accessories. Models were assessed in real SPS-focused reef setups where clarity and nutrient export matter, and scored on how cleanly they accept Apex probes and Reef Octopus skimmers.

We ignored brand loyalty, marketing claims about "reef-ready" volume, and total gallon ratings quoted without a drained-down working level, since a sump running full is a flood waiting on a power cut. We also set aside cosmetic polish, custom color options, and bundled freebies that don't change filtration. Warranty length was noted but not weighted, because sump failures are almost always plumbing or overflow errors, not manufacturing defects.

Related questions

How big should a sump be relative to the display tank?

A common target is 20–30% of display volume, so a 75-gallon reef pairs well with a 30–36 gallon sump like the Ruby 36e or CL-36. Bigger buys dilution and stability, but the real constraint is your stand opening. Measure the door width, not just the interior, since a 36" sump often will not clear a 36" stand.

Does the sump need to hold the full drain-down volume?

Yes. When the return pump stops, everything above the return nozzle and in the overflow drains into the sump. Fill the display, kill the pump, and mark where the sump water settles. That mark is your maximum normal operating level. A 30-gallon sump routinely runs at 18–22 gallons for exactly this reason.

Is acrylic or glass better for a reef sump?

Acrylic is lighter, easier to drill for probes and ports, and bonds chemically at the seams. Glass resists scratches and stays clearer over years of mag-float cleaning, but the CL-24 weighs 35 lbs empty and the CL-36 more. If you are lifting the sump into a finished stand alone, acrylic wins on practicality.

What causes micro-bubbles coming out of the return?

Usually the bubble trap is being overwhelmed by flow, or the skimmer is dumping air downstream of the baffles. Dual-weir designs like the Ruby 36e handle 1,500 GPH before they break down. Also check the return pump intake for a small air leak at the union — that fizzes constantly and gets blamed on baffles.

Do I need a refugium chamber at all?

Only if you plan to run chaeto, mangroves, or a pod population. A refugium exports nitrate and phosphate biologically and buffers pH overnight when lit on a reverse cycle. Skip it if you dose carbon or run a scrubber, and use that chamber for reactors instead. Fiji Cube's 10-gallon refugium is the largest here.

How many filter socks does a reef tank actually need?

Sock count follows drain count, not tank size. One 200-micron sock per drain line is standard, so a dual-drain 75-gallon needs two, not four. Extra holders like the Ruby's four-sock rack give you room to rotate socks without shutting flow down. Socks clog in three to five days on a fed reef.

Can I put a sump under a nano tank?

Yes, and it helps more than on a large system, because nano water chemistry swings fast. The Eshopps R-200 is 24" x 12" and adds roughly 20 gallons of buffer to a 30-gallon display. The limit is its 800 GPH rating and the stand's cabinet height, which must clear the skimmer body.

Does a sump make the tank noisier?

It can. Most noise comes from the overflow drain, not the sump itself, and a Herbie or Bean Animal standpipe silences it far more effectively than any baffle arrangement. Second source is the return pump vibrating against the sump floor — a rubber mat under it fixes most of that for a few dollars.

FAQ

What size sump do I need for a 75-gallon reef tank?

A 30–36 gallon sump gives room for a refugium, skimmer, and drain-down without running to the rim. The Ruby 36e at 36" x 18" and the CL-36 at 36" x 16" both fit that range. Confirm your stand's door opening clears the footprint before ordering, since 36" sumps rarely fit 36" stands.

Can I use a glass sump for a reef aquarium?

Yes. Glass sumps like the Alignment Reef CL-36 use 3/8" panels with silicone seams and resist scratching far better than acrylic. The trade-off is weight — plan on 40+ lbs empty and confirm your stand's floor panel is supported, not just spanning. Two people make installation into a finished stand much easier.

How do I prevent micro-bubbles in my sump?

Choose a sump with a real bubble trap; the Ruby 36e's dual-weir baffles are designed for it. Then match the return pump to the sump's rating rather than the display's turnover — pushing 1,500 GPH through a sump rated for 1,200 defeats any baffle. Let a new skimmer break in for a week before judging bubbles.

What is the best sump for SPS corals?

The Fiji Cube 36-Inch stands out, since its 10-gallon refugium gives real nutrient-export capacity and the UV port handles pathogens without an external canister. SPS tolerate less swing than softies, so prioritize total water volume and stable flow over chamber count. Pair it with a skimmer sized one tank class above your display.

Do I need a filter sock holder in my sump?

A holder makes socks practical, but socks are optional. They capture particulate before it breaks down, reducing nitrate load, and most reefers run 200-micron. The catch is maintenance: an unchanged sock becomes a nitrate factory in under a week. If you cannot commit to swapping them, run filter floss or nothing at all.

How much does a custom reef sump cost?

This list spans $399 for the Eshopps R-200 to $1,199 for the Reef Octopus VarioS 36. Mid-range models like the CL-36 land near $849. Budget separately for the return pump, unless you buy the VarioS, which includes a DC pump rated at 1,200 GPH and offsets much of its higher sticker price.

Can I use a sump with a nano tank?

Yes. The Eshopps R-200 holds about 20 gallons and fits under 30" stands, serving nano displays up to roughly 40 gallons. Match your return pump to its 800 GPH ceiling. The added volume noticeably slows temperature and salinity swings, which is the single biggest stability problem on small reef systems.

What is the difference between the Ruby 36e and the Crystal 36?

Both are 36" x 18" acrylic with a 7-gallon refugium and 1,500 GPH capacity. The Crystal 36 runs $1,049 with a fully transparent body for easy water-level checks, while the Ruby 36e adds the UV sterilizer return port for $1,099. If you plan on UV, the $50 difference is worth it.

Do I need a controller-ready sump?

Only if you already run or plan to run an Apex or similar. Probe holders keep pH, ORP, and temperature probes at a fixed depth in stable flow, which matters more for reading accuracy than most people expect. The Ruby 36e holds four probes; the Sapphire 26 and VarioS 36 hold three.

How often should I clean the sump itself?

Wipe the skimmer neck weekly, swap socks every three to five days, and pull detritus from the first chamber monthly with a turkey baster and siphon. A full teardown is rarely needed. If detritus accumulates faster than that, your first chamber flow is too slow or your drain is dumping directly onto the floor panel.

Sources

• https://www.bulkreefsupply.com/
• https://reefbuilders.com/
• https://www.reef2reef.com/
• https://www.marinedepot.com/
• https://www.neptunesystems.com/apex/
• https://www.saltwateraquarium.com/
• https://aquacave.com/
• https://www.advancedaquarist.com/

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