Red Sea REEFER G3 DELUXE Aquarium System 300

• 301 L total, on an 89.9 × 57.4 cm footprint – a 247 L rimless display over a 57 L sump, the largest sump in the 170–300 line.
• 2 × ReefLED G2 115 fixtures and mounting arms included – 115 W each, roughly 500 PAR at the surface falling to around 150 PAR at 50 cm, tunable white spectrum, rated to 60 cm maximum water depth.
• ReefATO+ built in – automatic top-off with a titanium water-level sensor, integrated thermometer and leak detection, standard on every G3 model.
• Redesigned G3 sump – REEF-SPEC, ReefMat-ready, with a dedicated skimmer chamber and a bubble-trap labyrinth ahead of the pump draw.
• Rimless, ultra-clear glass – beveled-edge front panel along the full 89.9 cm length.
• Pre-glued sump plumbing – the downpipe, return line and ReefGate flow valve arrive assembled.

• REEFER G3 300 rimless display aquarium
• Marine-spec cabinet in your choice of black or white
• REEF-SPEC glass sump with pre-glued plumbing and ReefGate flow valve
• 2 × ReefLED G2 115 LED fixtures with mounting arms
• ReefATO+ automatic top-off system, with water-level sensor, thermometer and leak detector
• Mechanical filtration media (filter socks and media cups)

Not included: return pump, protein skimmer, heater, the ReefMat fleece filter itself (the sump is only pre-fitted to accept one), any additional controller hub, and aquascaping rock, sand or livestock.

Floor loading: at approximately 470 kg filled with water alone – before aquascaping rock, sand or livestock – this is a load-bearing consideration on any floor above ground level. Add your own estimated rock and sand weight on top of this figure, and have a qualified professional confirm the floor can carry it before installation.

All four current REEFER G3 sizes share the same sump architecture, ReefGate valve and ReefATO+ system – the differences are footprint, volume, and how many ReefLED G2 115 fixtures the Deluxe package includes.

The 300 shares its 89.9 cm length with the 250 but is 7.4 cm deeper, with a 15 L larger sump and 56 L more total volume – the same footprint on the floor, more water and filtration behind it. Beyond the 300, the next step up in Red Sea's range is the S-series (including the S-700 we also stock), which moves to a substantially larger footprint rather than a further increment on this one.

Suitable for: a reefer who can commit 89.9 × 57.4 cm of floor space and wants the largest sump and water volume available in the 170–300 G3 range, with lighting already covering the full span.

Not suitable for: an install on an unconfirmed suspended floor – check the load rating first – or anyone expecting a plug-and-play kit; a return pump and, if wanted, a skimmer or ReefMat are still separate purchases.

Rinse or replace the sump's micron filter socks weekly, more often while cycling. Keep both ReefLED fan intakes free of salt dust. Wipe the ReefATO+ sensor periodically to prevent salt creep causing false top-off readings.

Run both ReefLED fixtures, the ATO pump and any added equipment on 240 V AU-approved supplies with an RCD, with mains connections above the water line and a drip loop. See the floor-loading note above before installing.

• Red Sea ReefRun G2 8000 DC Pump or Red Sea ReefRun G2 12000 DC Pump – return pump options for a 300-class sump.
• Red Sea Reefer DC Skimmer 600 – sized for the 300's skimmer chamber and bioload.
• Red Sea ReefMat Filter 500 – drops into the ReefMat-ready sump chamber, sized for the larger 57 L sump.
• Red Sea ReefLED 90/G2 115 Universal Mounting Arm – for a third fixture if you want tighter PAR uniformity across the full length.
• Red Sea Coral Pro Salt, 20 kg refill – for the initial fill and ongoing water changes on a 301 L system.
• Red Sea Seawater Refractometer – check salinity before any new mix goes in.

Red Sea covers the aquarium and cabinet for 36 months from purchase, extendable to 5 years total at no cost if you register within 90 days – Australia is an eligible market. The extension covers the structural integrity of the glass and cabinet only; the ReefLED fixtures and ReefATO+ carry their own 24-month manufacturer warranty. These terms sit in addition to your rights under the Australian Consumer Law, which are not limited or excluded by them. As a large glass and cabinet item, this ships as a freight delivery – confirm access and unloading arrangements with us before ordering.

How much does the filled system weigh, and is that a floor-loading concern?

Approximately 470 kg with water alone, before rock, sand or livestock. On a suspended or upper floor, get the load confirmed by a qualified professional before installing.

Does the REEFER G3 Deluxe 300 include a return pump?

No. A ReefRun G2 8000 or 12000 DC pump, sold separately, suits this sump size.

What's the difference between the 300 and the 250?

Same 89.9 cm length. The 300 is 7.4 cm deeper, with a 15 L larger sump and 56 L more total volume – the largest of the two.

Is the auto top-off included?

Yes. ReefATO+ ships standard on every REEFER G3 model, including this one. You'll still need your own top-up water reservoir.

Is there anything bigger than the 300 in the standard REEFER G3 line?

Not on the same footprint. The next step up is Red Sea's S-series – including the REEFER G3 S-700 we also stock – which is a substantially larger, differently proportioned system rather than a bigger version of the 300.