Red Sea REEFER 200 G3 — Rimless 52.8 gal Reef Aquarium with REEF-SPEC Sump and ReefATO+

The REEFER 200 G3 is the smallest of Red Sea's straight REEFER systems to carry a full glass sump. On a 60 cm (23.6") footprint you get a rimless ultra-clear tank, a marine-grade plywood cabinet, a 42 L (11.1 gal) REEF-SPEC sump and the ReefATO+ auto top-off — the plumbing logic of a large reef, folded into something that fits a living room wall.

The ReefATO+, installed on video

The ReefATO+ ships with the tank, and it is the piece that changes daily life the most: it replaces evaporated water and holds salinity steady while you are at work. Here is the install, filmed at our Laval store.

Official Red Sea figures

• Total system water volume: 200 L (52.8 US gal)
• Display tank volume: 158 L (41.7 US gal)
• Sump volume: 42 L (11.1 US gal)
• Display tank (L × W × H): 60 × 57.5 × 53 cm (23.6 × 22.6 × 20.9 in)
• Total system height: 140 cm (55.1 in), excluding the light unit
• Ultra-clear glass: front 10 mm (0.4 in) · sides 12 mm (0.5 in) · bottom 10 mm (0.4 in) · back 8 mm (0.3 in)
• Rim type: rimless, no internal brace, bevelled edges
• Cabinet colours: white or black

What the G3 generation changed

The G3 rework is about flow. Red Sea claims up to 50% more circulation from redesigned piping, and the downpipe inlet is now a widened rectangle that breaks up turbulence — and with it, the sound of falling water. On top of that sits the ReefGate, a high-precision valve on the main downpipe that lets you dial in the overflow water level in small increments. Set it carefully and the system runs very discreetly; set it roughly and it will remind you with a permanent gurgle. It is worth spending fifteen minutes on it the day you fill the tank.

Weight and clearances

These are the numbers nobody checks before buying and everybody thinks about after. Red Sea rates the full running system at 315 kg (694 lb) — that is what your floor carries. The empty glass tank alone is 40 kg (88 lb), so plan on at least two people to lift it onto the cabinet.

The manual asks for a minimum of 10 cm (3.9 in) behind the tank for cabling and airflow, and recommends roughly 60 cm (23.6 in) on each side so you can reach the back. The cabinet top sits about 86 cm (33.9 in) off the floor. Red Sea also suggests keeping the room near 22 °C (71.6 °F), away from direct sun and air-conditioning vents.

What is in the box — and what is not

Included: the glass tank, the flat-pack cabinet with adjustable feet, the ReefMat-Ready glass sump (optional refugium divider), the internal plumbing with return nozzle, and the ReefATO+ smart top-off with its temperature probe and leak detector.

Not included: lighting, return pump, skimmer, wave pumps and ReefMat. And one detail many listings quietly skip: REEFER G3 systems come with no top-off water reservoir. The series manual says so in plain words. The ReefATO+ needs something to draw from — a jug works, a ReefCan 18 or 40 tucks into the cabinet properly. If you read anywhere that a reservoir is built into this model's sump, that claim does not come from the manufacturer.

The gear Red Sea itself fits to this model

Rather than invent "recommended setups", here is what Red Sea packs into its own REEFER MAX 200 G3 — the manufacturer's own sizing for this exact volume:

• 1 × ReefLED G2 115 — the unit specified for a tank this long
• 1 × ReefWave 25 (7,500 L/h · 1,981 gph) for circulation
• 1 × ReefRun G2 4000 (2,000–4,000 L/h · 530–1,060 gph) as the return pump
• 1 × RSK 300 DC (water flow 1,000 L/h · 264 gph, air flow 500 L/h · 132 gph)
• 1 × ReefMat 250, which takes the place of the filter sock drawer

Nothing forces you to buy it all at once, and nothing forces you to stay inside one brand. But if you are unsure about sizing, that list is the manufacturer's answer rather than an opinion.

Sump and mechanical filtration

Surface water leaves through removable combs, drops down the main pipe metered by the ReefGate, then passes the mechanical filtration module — 225 micron socks or media cups, your choice. Red Sea suggests keeping at least three sets of socks in rotation, so one set dries after washing while another is in service. That module lifts out entirely to make room for a ReefMat, with no sump modification. A bubble trap with a coarse sponge protects the return pump, and the constant-level pump chamber is the one the ReefATO+ watches.

Our advice

This is a nice little aquarium — practical, it does not eat your floor space, and it is a good system for a first step into reef keeping: easy to understand, easy to maintain.

My advice before you commit to a small tank like this one: think hard about what you actually want. It is always the same story with small aquariums — people often have the budget for something bigger, but they pick small out of caution, or for all sorts of reasons, and they quickly wish they had gone larger. If you want small and you love small, that is wonderful. But if you are not sure, take the time to weigh your budget, the dimensions and the space you have — because with a small aquarium, you run out of room fast. The REEFER 250 G3 is the next size up, and it is worth comparing the two before you decide.

— Stéphane, Aquarium ReefSolution

We build the system with you

A reef system is not bought in a single order, and that is perfectly fine. Write to us or come to the Laval store with your budget and your project: we work out the configuration that matches what you expect from the tank, starting with the essentials and adding the rest at your own pace. We do this every day, and it costs nothing.

Warranty

REEFER G3 systems carry a 3-year worldwide warranty. Canada is one of the countries where registering the system within 90 days of purchase adds 2 more years at no charge — 5 years in total. Coverage applies to the glass tank and the cabinet, is limited to the original owner and requires proof of purchase. Equipment supplied with the system, such as the ReefATO+, carries its own separate warranty.

Why buy from ReefSolution

• Authorized Red Sea dealer in Canada, with factory support behind the warranty
• Physical store in Laval, Quebec: see REEFER systems running before you commit
• Shipping across Canada. Free shipping available depending on order value.
• After-sales support in English and French
• For top-off water, an RO/DI unit is the one purchase nobody plans and everybody ends up making

Frequently asked questions

How many gallons is the Red Sea REEFER 200 G3?

The complete system holds 200 L, or 52.8 US gallons according to Red Sea's own configurator. The display tank alone holds 158 L (41.7 US gal) and the sump 42 L (11.1 US gal).

Is the REEFER 200 G3 an all in one reef tank?

Not in the usual sense. It ships as a complete water-management platform — tank, cabinet, sump, plumbing and the ReefATO+ top-off — but lighting, return pump, skimmer, wave pumps and roller filter are sold separately. Red Sea's fully equipped version is sold under the REEFER MAX name; on the standard model, the equipment choice is yours.

What return pump does a REEFER 200 G3 need?

The Red Sea series manual recommends a ReefRun G2 4000, rated 2,000 to 4,000 L/h (530 to 1,060 gph). It is not included with the system.

Is the REEFER 200 G3 rimless?

Yes. Across the straight REEFER range, models up to the 350 are rimless with bevelled edges; the internal brace starts at the 425. Aluminium front reinforcement applies only from the 525 upward.

Is a REEFER 200 G3 a good nano reef tank for a beginner?

It is a solid starting point: sump, overflow and top-off are engineered together, which avoids the improvised plumbing that causes most early surprises. The real question is not difficulty, it is volume — 158 L fills up quickly once corals and fish start appealing to you. Read our advice above before deciding.

How much does a REEFER 200 G3 weigh when full?

Red Sea rates the complete running system at 315 kg (694 lb). That is the load your floor carries, and it is worth checking before buying if the tank is going upstairs.