Red Sea REEFER 300 G3 — Deep Rimless Reef Tank, 300 L on a 90 cm Footprint

Red Sea Reefer 300 G3 — Depth That Transforms Your Reef

The Reefer 300 G3 is a complete reef platform built for aquarists short on wall space who refuse to give up depth. Its rimless, reinforced ultra-clear glass tank delivers a true three-dimensional reefscape: more relief in your aquascape, more front-to-back swimming room, more freedom to place corals exactly where they belong.

Official Red Sea numbers: display tank 90 cm (35.4 in) long × 57.5 cm (22.6 in) deep × 55 cm (21.7 in) high. Total system volume: 300 L (79.2 US gal) — 246 L (65 US gal) display plus a 54 L (14.3 US gal) REEF-SPEC sump. Total height with cabinet: 142 cm (55.9 in).

The REEFER G3 Series on Video

Official Specifications

Display tank: rimless reinforced ultra-clear glass — 12 mm front, sides and bottom, 10 mm rear. No frame, no brace: an unobstructed view across the entire front and sides.

Cabinet: reinforced marine-grade plywood, water-resistant and built for humid environments, with adjustable feet for precise leveling. Complete system height: 142 cm (55.9 in).

REEF-SPEC sump, 54 L (14.3 US gal): dedicated mechanical filtration and media compartment, skimmer chamber with adjustable water height, micro-bubble trap and a controlled return zone.

Pre-assembled, glue-free plumbing: silent down-flow regulated by a high-precision gate valve, hydrodynamically improved piping, and an integrated emergency overflow that protects the system if flow ever varies.

ReefATO+ Ready: the system is prepared for Red Sea's ReefATO+ auto top-off module. Note: the Red Sea manual states that REEFER G3 systems do not include a reservoir for the top-off water — plan for one separately.

300 vs 250: Same Footprint, More Depth

The Reefer 300 G3 shares the exact 90 cm (35.4 in) length of the Reefer 250 G3, but adds 7.5 cm of depth and 2 cm of tank height. The payoff: volume climbs from 250 L to 300 L, the aquascape becomes genuinely three-dimensional, and water circulates with fewer dead spots. It fills the gap perfectly between the 250, which some find limiting, and the 350, which needs 120 cm of wall space.

The Gear We Recommend

Red Sea's lighting recommendation for this model is 2 ReefLED G2 115 units in the DLX configuration — that's our ReefLED G2 lineup. For circulation, pair a ReefRun G2 DC return pump with ReefWave 45 wave pumps. The Red Sea 600 DC skimmer drops straight into the sump's dedicated chamber, and the ReefMat 500 automates mechanical filtration. For auto top-off, add the ReefCan reservoir, and for pure water, an AquaticLife 100 GPD RO/DI unit. Finally, the 24 in Net Cover protects jumping fish — more on that below.

What's Included / What to Plan For

Included: rimless ultra-clear tank, reinforced marine cabinet, REEF-SPEC sump, silent down-flow system, pre-assembled plumbing with high-precision gate valve, emergency overflow, ReefATO+ preparation.

Plan for: lighting, return pump, wave pumps, protein skimmer, mechanical filtration, top-off reservoir, RO/DI unit, salt, substrate and rock.

Our Advice

The Reefer 300 G3 is the ideal choice when you're short on length but still want real depth. What makes a deep tank special is that beautiful three-dimensional effect. Yes, less length is a compromise for large fish, but you can absolutely build something stunning.

Mistakes to avoid: always run proper circulation (three pumps minimum), a well-tuned skimmer, and a quiet, properly set down-flow. Just ask us — we can help you find the setup that fits.

The Net Cover matters. As soon as you keep jumping fish (clownfish, wrasses, firefish…), get a Net Cover. Finding your little fish on the floor in the morning is hard, especially when it's a family hobby and the kids have named them.

The Reefer 300 is for people who don't have the space for a 350 but find the 250 too small. Same length as the 250 (90 cm), with more width and depth — so more three dimensions, more volume for flow, more flexibility. And here at ReefSolution, we're here to help: we can call you, talk it through, and you can drop by the store anytime.

— Stéphane, Aquarium ReefSolution

Warranty

REEFER G3 systems carry a standard 3-year worldwide warranty on the glass tank and cabinet. In Canada, register your system at redseafish.com within 90 days of purchase and receive 2 additional years at no charge — 5 years total. Additional equipment (lighting, pumps, skimmer, ReefATO+) carries its own individual warranty.

Why Buy From ReefSolution?

When you buy an aquarium from us, we actually help: we can call you, discuss your project, and you're always welcome at the store in Laval. Installation, equipment choices, flow tuning, coral selection — we're there before and after the sale.

Secure shipping across Canada.

Frequently Asked Questions

Is the Reefer 300 G3 better for SPS or LPS corals?

Both. With the right lighting and well-planned flow, its 57.5 cm (22.6 in) depth supports a solid SPS reef as well as a mixed SPS/LPS display. That depth is exactly what gives you the flexibility to place each coral at the right height under the light.

Which return pump should I choose for the Reefer 300 G3?

The ReefRun G2 DC is the natural pick within the Red Sea ecosystem: programmable flow through the ReefBeat app and direct integration into the REEF-SPEC sump. Contact us to confirm the right flow rate for your full setup.

Do I really need a Net Cover on a rimless tank?

If you keep jumping fish — and nearly every reefer ends up with one — yes. A rimless tank has no edge to stop a jumper. The 24 in Net Cover trims to size and installs in minutes.