Red Sea REEFER 425 G3 — 114 Gal Euro-Brace Reef Aquarium 47 in with ReefATO+

The Red Sea REEFER 425 G3 takes the same 47-inch footprint as the REEFER 350 G3 and pushes it 4 inches deeper: 60 cm front to back instead of 50. That adds 70 litres of display water without claiming any extra wall space, and gives your aquascape real three-dimensional room to work with. It is also the first model in the lineup built with a Euro-brace frame and 15 mm side glass.

Watch Stéphane walk through the auto top-off install on his own system — the same ReefATO+ kit that ships with the 425:

Official REEFER 425 G3 specifications

• Total system volume: 433 L (114.4 US gal)
• Display volume: 343 L (90.6 US gal)
• In-cabinet sump volume: 90 L
• Display tank dimensions: 120 × 60 × 55 cm (47 in long)
• Total system height: 142 cm
• Ultra-clear glass: 12 mm front, bottom and back; 15 mm sides
• Rim type: Euro-brace
• Operating weight: 690 kg (1520 lb) — glass tank alone: 95 kg (210 lb)

The cabinet top sits 86 cm (34 in) off the floor per the manufacturer. Red Sea calls for 10 cm (4 in) of clearance behind the system and 60 cm (24 in) on one side for access, in a room held at a stable 22 °C (72 °F).

Why Euro-brace at this size

At 60 cm deep and 433 L, Red Sea reinforces the structure with a Euro-brace frame and 15 mm glass on the sides. The brace reads as a thin band along the top edge — the viewing panel stays wide open while overall rigidity goes up. The downpipe carries the high-precision ReefGate valve, which sets the water level in the overflow box for a steady, controlled flow down to the sump.

What's in the box — and what isn't

Included: the Euro-brace glass tank, the marine-grade plywood cabinet with adjustable feet, the ReefMat-ready REEF-SPEC sump with 225-micron mechanical filtration, the internal plumbing kit with ReefGate valve, and the ReefATO+ kit for evaporation top-off.

Not included: the return pump, lighting, protein skimmer, wave pumps — and the top-off water reservoir. Red Sea states it plainly: G3 systems ship without a reservoir for the ATO. The ReefCan was designed for exactly that job.

Red Sea's published MAX configuration for the 425

The official MyREEFER configurator recommends for this model: 2 units of ReefLED G2 115 or 170 for lighting, 1 ReefRun G2 6000 return pump (3600–6500 lph), the REEFER Skimmer 600 and the ReefMat 500 both flagged "Best size for SPS", plus 2 ReefWave 45 wave pumps. At 433 L total, the system lands squarely within the ReefMat 500's rated range.

Plan for these as well

An RO/DI unit for top-off and mixing water, a ReefCan as the ReefATO+ reservoir, and a Net Cover screen kit if you keep jumpers. Red Sea suggests keeping at least 3 sets of 225-micron filter socks in rotation. Need more length? The REEFER 525 G3 stretches the same platform to 59 inches.

Our advice

The REEFER 425 G3 is the 350's big brother: same length, but a much wider three-dimensional sense of depth — and for swimming room and the size of fish you can keep, that changes things. At this size, the Euro-brace is no longer optional: it stiffens the tank. And honestly, you barely see it — just a thin black line along the top. Red Sea's Euro-braces are so well made you forget they're there. Always run an RO/DI unit when you set up your aquarium: RO water is the foundation of a healthy tank, and we strongly recommend it. All of that comes with the 5-year warranty and the support behind it. And remember: when you buy an aquarium from us, we call you, we help you, and if you have questions, we're always there to back you up — a reef tank takes knowledge, and that comes with time and good support. — Stéphane

Warranty

REEFER G3 systems carry a standard 3-year warranty. Register your aquarium on Red Sea's website within 90 days of purchase and you receive 2 more years — 5 years total — at no charge. Canada is on the list of eligible countries.

Why buy from ReefSolution

Authorized Red Sea dealer in Quebec. Secure delivery across Canada. Guidance before and after the sale from a team that runs its own reef tanks.

Frequently asked questions

What's the difference between the REEFER 350 G3 and the REEFER 425 G3?

Both are 120 cm (47 in) long. The 425 is 10 cm deeper (60 cm vs 50), which raises display volume from 273 to 343 L and total volume from 342 to 433 L. The 350 is rimless; the 425 moves to a Euro-brace frame with 15 mm sides.

Does the REEFER 425 G3 come with a return pump and skimmer?

No. The system includes the tank, cabinet, REEF-SPEC sump, plumbing with the ReefGate valve, and the ReefATO+ kit. Return pump, lighting, skimmer and flow are chosen separately to match your build.

What return pump does the REEFER 425 G3 need?

The series manual recommends one ReefRun G2 6000, adjustable from 3600 to 6500 lph (950–1700 gph).

Is the ATO water reservoir included?

No. The ReefATO+ kit is supplied, but the manufacturer specifies that G3 systems do not include a top-off reservoir. Red Sea's ReefCan fills that role inside or beside the cabinet.