Red Sea REEFER 625 G3 — 163.8 gal Euro-Braced Reef Aquarium 59 in with ReefATO+

Red Sea REEFER 625 G3 — the big-volume reef tank on a 59-inch footprint

The REEFER 625 G3 shares its 59-inch length with the REEFER 525 G3, then pulls away where it matters: a display that is 65 cm (25.6 in) deep and 60 cm (23.6 in) tall, for 163.8 US gallons of total system volume. That extra depth changes how a reef gets built — rockwork gains true front-to-back perspective, the foreground opens up, and corals get breathing room that standard footprints cannot offer. This is the platform for ambitious saltwater projects: an established SPS reef, a large mixed reef aquarium, or the anchor piece of a living space. It is also a footprint we know first-hand: its little brother, the 525 G3, is the very system we run ourselves at the store, and we filmed a whole video series on it — sump, return pump and flow — on the same 59-inch platform and sump architecture as the 625 (videos in French, on the French side of this page).

Official REEFER 625 G3 specifications

• Total system volume: 620 L / 163.8 US gal
• Display volume: 497 L
• Sump volume: 123 L
• Display tank: 59 in (150 cm) long × 65 cm wide × 60 cm tall
• Total system height: 148 cm
• Ultra-clear glass: 19 mm front, sides and back; 15 mm bottom
• Frame: Euro-braced
• Operating weight: 930 kg / 2,060 lb
• Glass aquarium alone: 155 kg / 340 lb

Source: Red Sea's official REEFER G3 Models & Specs table and the series manual.

Floor load, clearances and placement

At 2,060 lb in operation, the floor under this system has to be rated for the load. Red Sea puts the cabinet top at 86 cm (34 in) from the floor and asks for 10 cm (4 in) of clearance behind the tank for cables and ventilation, plus 60 cm (24 in) free on one side to reach the back. A ventilated room at a stable 22°C (72°F), away from direct sun and heating vents, completes the ideal spot.

Euro-bracing, 19 mm glass and aluminum supports

The 625 carries the thickest glass in the straight REEFER line: 19 mm on three panels. Models 425 and up are Euro-braced for extra strength, and from the 525 up, the marine-spec plywood cabinet adds front aluminum supports — the 625 gets both. Epoxy-painted doors, stainless steel hinges and adjustable leveling feet round out a cabinet built to live around saltwater. The redesigned G3 piping delivers, per Red Sea, up to 50% more water circulation than the previous generation, and the ReefGate high-precision gate valve dials in the drain for near-silent running.

What's in the box — and the official MAX configuration

Included: the glass tank, the self-assembly cabinet, the ReefMat-ready REEF-SPEC sump with micron filter bags and media cups, the glue-free internal piping kit, and the ReefATO+ smart top-off with temperature probe and leak detector. The return pump, protein skimmer, wave pumps, lighting and top-off reservoir are sold separately.

To equip the 625, Red Sea publishes its MAX configuration: 2 × ReefLED G2 170 lights, 2 × ReefWave 45 gyre pumps, one ReefRun G2 8000 return pump — the same model the series manual recommends, and the one running on our own 59-inch system — the RSK 900 DC skimmer and the ReefMat 1200 roller filter.

Plan for these as well

The ReefATO+ comes in the box, but its reservoir never does: the ReefCan slides into the cabinet and connects directly. Plan an RO water source too — an AquaticLife 100 GPD RO/DI unit keeps up with a system this size — and, if you keep jumpers, a Net Cover screen kit cut to size.

Sump and plumbing

Surface water flows through the removable surface skimmer into the enlarged rectangular downflow inlet, which cuts turbulence and flow noise. The ReefGate valve holds the overflow-box level between the two intakes — that one adjustment is what makes the drain run quiet. Inside the sump: 225-micron filter bags (Red Sea suggests keeping three sets), an adjustable-height skimmer chamber, a bubble trap ahead of the pump section, and a constant pump-chamber level held by the ReefATO+ for stable head pressure on the return pump.

Our advice

"When we picked our own 525 at home, we hesitated with the 625. It's a magnificent aquarium — with the 625 you're in the big leagues, playing with the majors. But for our needs and our budget, the extra thousand dollars wasn't justified, and we still love our 525 today. That's the real question: assess your needs. And if you'd like help doing that, call us — it will be our pleasure."

"For lighting on a big tank like this one, I recommend the ReefLED G2 170s: the single focus point gives a truly beautiful look. It's what we run on ours — we worked with other brands for a long time, and we're slowly switching everything over. And put this aquarium in a living space, the living room or the kitchen: showcase it so the whole family enjoys it. That's how an aquarium becomes a family passion you keep for years, not a hobby that stalls. Buying a system is easy; managing it long term and having someone to talk to when a question comes up — that's worth gold." — Stéphane, Aquarium ReefSolution

3-year warranty, extendable to 5 years

Every REEFER G3 carries a 3-year warranty. Register your system with Red Sea within 90 days of purchase and coverage of the structural integrity of the glass and cabinet extends to 5 years at no charge — Canada is on the eligible list.

Why buy your REEFER 625 from ReefSolution

ReefSolution isn't just a transactional website. Elsewhere you order online and never hear from anyone again; here, when you buy an aquarium, we call you. We go through your questions, what's missing, what you want to add or remove, and we teach you how — we don't drop you after the sale. Thirty years of experience and every video we've filmed — nobody can replace that. Secure delivery across Canada at a flat $100 rate.

FAQ — Red Sea REEFER 625 G3

What is the difference between the REEFER 525 G3 and the REEFER 625 G3?

Both are 59 inches long. The 625 runs deeper (65 cm vs 60), taller (60 cm of display vs 55) and moves from 15 mm to 19 mm glass on three panels: 163.8 gallons of total volume versus 142.7, with a 123 L sump versus 116 L. On the same footprint length, it is the largest volume in the straight REEFER line under the 71-inch format.

Does the REEFER 625 G3 come with a skimmer and return pump?

No. Red Sea's official spec table lists the main pump, protein skimmer, wave pumps and lighting as not included. The series manual recommends the ReefRun G2 8000 return pump, and Red Sea's MAX configuration pairs the RSK 900 DC skimmer and the ReefMat 1200 with this model.

What lighting should I choose for a 160-gallon reef tank?

Red Sea publishes two options for the 625 G3: 3 × ReefLED G2 115 or 2 × ReefLED G2 170. At ReefSolution we recommend the 170s on this format — the single focus point delivers the look we run on our own display.