Red Sea REEFER 750 G3 — 198.1 gal Reef Aquarium 71 in with Extension Sump

Red Sea REEFER 750 G3 — the longest straight REEFER, at 71 inches

With a 180 cm (71 in) display and 750 litres of total volume (198.1 US gal), the REEFER 750 G3 tops Red Sea's straight line. Its 600 L display opens the door to fish schools, full-grown tangs and mature coral colonies, while the cabinet holds both the 150 L REEF-SPEC sump and an included glass extension sump — a component the series manual reserves for the largest models in the range. The sump architecture and recommended return pump are the same as on the 525 G3 we run ourselves at the store — the video series on this page (in French) was filmed directly on it.

Official REEFER 750 G3 specifications

• Total system volume: 750 L / 198.1 US gal
• Display volume: 600 L
• In-cabinet sump: 150 L, plus the included glass extension sump
• Display tank: 71 in (180 cm) long × 65 cm wide × 60 cm tall
• Total system height: 148 cm
• Ultra-clear glass: 19 mm on the front, sides, back and bottom
• Frame: Euro-braced
• Operating weight: 1,110 kg / 2,460 lb
• Glass aquarium alone: 195 kg / 430 lb

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

Floor load, clearances and handling

Running, this system weighs 2,460 lb (1,110 kg): the floor has to be rated for it before delivery day. The glass tank alone is 430 lb (195 kg) — plan the crew to lift it onto the cabinet. Red Sea puts the cabinet top at 86 cm (34 in) from the floor and calls for 10 cm (4 in) of clearance behind the tank for cables and ventilation, plus 60 cm (24 in) free on one side for rear access. Aim for a ventilated room at a stable 22°C (72°F), away from direct sun and heating vents.

19 mm glass on every panel

The 750 is the only straight REEFER whose glass reaches 19 mm everywhere — front, sides, back and bottom. Euro-bracing (models 425 and up) and the cabinet's front aluminum supports (525 and up) are naturally on board, along with marine-spec plywood, epoxy doors, stainless hinges and leveling feet. The redesigned G3 piping delivers, per Red Sea, up to 50% more water circulation than the previous generation, dialed in by the ReefGate high-precision gate valve.

What's in the boxes — 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 glass extension sump, the glue-free internal piping kit, and the ReefATO+ smart top-off with temperature probe and leak detector. Return pump, protein skimmer, wave pumps, lighting and the top-off reservoir are chosen separately.

Red Sea's published MAX configuration for the 750: 3 × ReefLED G2 170 lights, 2 × ReefWave 45 gyre pumps, one ReefRun G2 8000 return pump — the model the series manual names for the 750 — the RSK 900 DC skimmer and the ReefMat 1200 roller filter.

Plan for these as well

The ReefATO+ reservoir never ships with any G3: the ReefCan fits inside the cabinet and connects directly. A 198-gallon system consumes RO water — an AquaticLife 100 GPD RO/DI unit covers the production — and since the tank is open-topped, a Net Cover screen cut to size protects jumping fish.

Sump and plumbing

The removable surface skimmer feeds the enlarged rectangular downflow inlet, which cuts turbulence and flow noise. The ReefGate valve locks the overflow-box level between the two intakes — the one adjustment that silences the drain. Inside the sump: 225-micron filter bags (Red Sea suggests 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 steady head pressure.

Our advice

"The 750 is a very big piece — we're not in beginner aquariums anymore. It's really for passionate hobbyists who want it in their kitchen or their living space: an aquarium that will last for years, give years of pleasure, and look superb. At this size, you'll practically never be limited on fish: you can keep more of them, and bigger ones. And a large volume like this is a stable environment — parameters drift more slowly, and everything living in it benefits. As with every open-top aquarium, put a cover on for the jumpers. That said, be honest with yourself: you need the budget that goes with a big aquarium like this — lighting, flow, salt, heating, everything scales up. If you're torn between the 625 and the 750, call us: assessing your needs before you buy is what makes the difference." — Stéphane, Aquarium ReefSolution

3-year warranty, extendable to 5 years

The base warranty covers the system for 3 years. Original purchasers who register their aquarium with Red Sea within 90 days receive 2 extra years at no charge on the structural integrity of the glass and cabinet — and Canada qualifies.

Why buy your REEFER 750 from ReefSolution

A purchase this size deserves better than an anonymous online cart. With us, buying an aquarium triggers a phone call: we go over your questions together, what your setup is missing, what you want to add or remove, and we show you how — before and after the sale. Thirty years in the trade and a library of videos filmed on our own systems: that's what stands behind every 750 we sell. Secure delivery across Canada at a flat $100 rate.

FAQ — Red Sea REEFER 750 G3

What is the difference between the REEFER 625 G3 and the REEFER 750 G3?

The 750 stretches the display from 59 to 71 inches at the same depth and height (65 × 60 cm): 198.1 gallons of total volume versus 163.8. Its glass reaches 19 mm on every panel including the bottom (15 mm on the 625's bottom), and it is the only one of the two shipped with the extension sump. Its MAX configuration moves up to 3 ReefLED G2 170 lights instead of 2.

Does the REEFER 750 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, and Red Sea's MAX configuration pairs the RSK 900 DC skimmer and the ReefMat 1200 with the 750.

What is the extension sump on the REEFER 750 G3?

The series manual lists a glass extension sump among the 750's included components — an item reserved for the largest models in the range (750, S-850, S-1000 and PS-950). It adds volume and equipment space inside the cabinet, on top of the main 150 L sump.