Red Sea REEFER G3 Aquarium System S-550

• Wide, shallow rimless display – 448 L display volume in a 120 × 68 × 65 cm footprint, giving more width and floor-level viewing area than the same-length 350 without adding length.
• 19 mm ultra-clear glass – thicker front glass than the numbered 300/350 models, reflecting the S-550's greater width and water pressure.
• ReefATO+ auto top-off included – Red Sea's electronic top-off system, with temperature monitoring and leak detection, comes standard rather than as an upgrade.
• Aluminium cabinet – a different construction to the laminated-plywood cabinets on the numbered G3 range, with adjustable levelling feet, in black or white.
• Large 101 L sump with a slide-out control panel – pre-glued plumbing and room for equipment, with a slide-out panel for access to controls.
• 549 L total system volume – the figure to use for salt mix, dosing and medication calculations, not the smaller 448 L display-only figure.

• REEFER G3 S-550 aquarium, rimless ultra-clear glass with internal overflow
• Marine-spec aluminium cabinet, in the colour shown
• Glass sump with pre-glued plumbing and slide-out control panel
• ReefATO+ auto top-off system, with temperature monitoring and leak detection

• Return pump
• Protein skimmer
• Lighting
• ReefMat fleece roller filter
• Heater
• Salt, substrate, aquascape and livestock

This listing is the base G3-S platform: tank, aluminium cabinet, sump and auto top-off, with your choice of pump, skimmer and light fitted afterwards. Red Sea's REEFER MAX line ships as a complete kit, with a pump, skimmer and lighting already fitted – our Max 525 G3 is an example of what that inclusion level looks like. If you want a system that's ready to run on day one, check a MAX model rather than assuming this one includes it.

The S-550 breaks the length ladder the other four models follow. It shares the 350's 120 cm length but is significantly wider and deeper, giving more display volume than the 625 in a shorter footprint – the shape to choose when width matters more than length, such as a room where the tank sits across a shorter wall.

Every G3 model, including the S-550, ships with Red Sea's ReefATO+ electronic auto top-off as standard, with temperature monitoring and leak detection, rather than as an add-on. The S-550 uses an aluminium cabinet rather than the laminated-plywood cabinets on the numbered 300–750 range, and adds a slide-out control panel to the sump.

Suitable for: reef keepers who want a wide, shallow display – more floor-level viewing area and width for aquascaping – rather than a long, narrower footprint, and who are sourcing their own return pump, skimmer and lighting.

Not suitable for: anyone who wants a single purchase that includes a skimmer, return pump and lighting – that's Red Sea's MAX range, not this listing. Also not the right pick if a longer feature-wall footprint suits the room better than a wide one – the 625 or 750 cover that shape instead.

Red Sea's REEFER range carries a manufacturer's warranty of 3 years standard, extendable to 5 years total with registration within 90 days of purchase – provided in addition to your rights under Australian Consumer Law. Mains-powered components, including the ReefATO+ unit, run on 240 V / 50 Hz Australian supply. Red Sea does not publish an empty or filled weight for this system; as a floor-loading guide, the water alone in a full 549 L system weighs around 549 kg, before the glass, cabinet, sump, aquascape and livestock are counted. Get a professional opinion on your floor's load rating before committing to a spot, particularly upstairs or over an unsupported span. This is a large glass and cabinet item, typically shipped as a drop-ship item direct from the supplier rather than standard courier; the cabinet requires assembly.

• Red Sea Reefer DC Skimmer 600 – the skimmer Red Sea recommends alongside the S-550's sump on complete kits at this size.
• Red Sea Coral Pro Salt 20kg Refill Box – mixes enough saltwater for water changes on a system this size.
• Red Sea Seawater Refractometer – for checking salinity before the tank goes live.
• Red Sea Alkalinity Pro Reagent Refill Kit – alkalinity is the parameter reef keepers check most often once stocked.

Does the REEFER G3 S-550 include a return pump or skimmer?

No. This listing is the aquarium, sump, aluminium cabinet and ReefATO+ auto top-off only. A return pump and protein skimmer are sold separately, so you can size them to your stocking plan.

What does the 549 L figure on this listing mean?

It's the total system volume – display plus sump combined. Use that figure, not the 448 L display-only volume, for salt mix and dosing calculations.

How is the S-550 different from the numbered REEFER G3 models?

It's a wider, shallower shape rather than a longer one – 120 cm long like the 350, but significantly wider and deeper – and it uses an aluminium cabinet instead of the laminated-plywood cabinets on the 300–750 range.

What skimmer fits the S-550's sump?

Red Sea pairs the S-550 with its Reefer DC Skimmer 600 on complete kits at this size – a reasonable starting point, though your final choice should match your actual bioload.

How much does a full system weigh, and will my floor take it?

Red Sea doesn't publish a tank or cabinet weight for this model. The water alone in a full 549 L system weighs around 549 kg – worth checking your floor's load rating for a system this size, especially upstairs.