Red Sea Reefer Peninsula 500 G3 — Euro-Braced 137 Gal Peninsula Reef Tank Room Divider

The Red Sea Reefer Peninsula 500 G3 is a complete 519 L / 137.1 US gal peninsula reef tank built to stand in the middle of a room, one end against the wall, with two long views of the reef. The display measures 125 cm long — 49.2" per Red Sea — by 63.5 cm wide by 60 cm tall, with all filtration gathered at one end. New to this generation: the 500 now carries a Euro-brace, a change Red Sea itself flags as new.

Filmed at our store: the ReefATO+ that ships standard with every Peninsula G3, and how it keeps the water level steady day after day. This is the exact unit that will run inside the 500's cabinet.

The official numbers

Every figure below is taken from the specification table Red Sea publishes for this model.

• Total system water volume: 519 L — 137.1 US gal
• Display tank volume: 412 L — 108.8 US gal
• Sump volume: 106.6 L — 28.2 US gal
• Display tank length: 125 cm — 49.2"
• Display tank width: 63.5 cm — 25"
• Display tank height: 60 cm — 23.6" (excluding the light unit)
• Total system height: 160 cm — 63" (excluding the light unit)
• Ultra-clear front, side, bottom and back glass: 15 mm — 0.6"
• Rim type: Euro-brace — new to the G3 generation on this model
• Hydrodynamic piping with ReefGate valve — new to the G3 generation
• Cabinet: fortified plywood, with a dedicated chiller and hardware chamber

Weight, height and the space it needs

These figures come from the REEFER G3 series manual Red Sea publishes. They appear on no product page, and they are the ones that decide whether this saltwater aquarium fits your home.

• Total system weight once filled: 761 kg — 1,678 lb
• Glass tank alone, to be lifted onto the cabinet: 121 kg — 267 lb
• Height of the cabinet top: 100 cm — 40". Standard REEFER models sit at 86 cm (34"), so the Peninsula stands 14 cm taller.
• Clearance behind the tank: 10 cm — 4" minimum
• Recommended clearance on one side: 60 cm — 24", for access to the back
• Recommended room temperature: 22 °C — 72 °F

Red Sea presents these weights as approximate values in its manual. The 1,678 lb sits on the cabinet footprint, not spread across the room: it is the number to hand a contractor or an inspector if the tank is going on an upper floor of a wood-framed house. On a basement concrete slab the question does not arise.

The Euro-brace: what changed with the G3

The previous generation of the Peninsula 500 was a rimless tank. On the G3, Red Sea fits the 500 with a Euro-brace and presents the change as a new feature of the model. The top stays open — the brace runs along the perimeter, with no lid and no canopy.

If a fully rimless display is what you are after, it exists within the same range: the Peninsula 350 G3 is the only rimless Peninsula of the G3 generation — a shorter 96 cm format and a 352 L system. Between the two, the 500 adds 29 cm (11.4") of length and 167 L (44.1 gal) of volume.

As with any open-top reef aquarium, nothing stops a fish that decides to jump. Red Sea builds a framed Aquarium Net Cover for exactly this situation, cut to fit an open-top display.

What is included, and what is not

The Peninsula 500 G3 is sold as a foundation rather than a turnkey system. Red Sea includes the ReefATO+, its smart top-off unit that holds water volume and salinity steady, monitors temperature and detects leaks. The glass display, the glass sump, the complete plumbing and the cabinet come with the tank as well.

Not included: lighting, circulation, return pump, protein skimmer and automatic mechanical filtration. Red Sea also sells this exact tank as a fully equipped MAX system, and publishes the hardware it installs itself. That list is the best available reference when you spec your own build:

• Lighting: 2 x ReefLED G2 170
• Circulation: 2 x ReefWave 45 (15,000 lph — 3,963 gph)
• Return pump: 1 x ReefRun G2 8000 (4,100-8,300 lph — 1,080-2,200 gph) — also the model Red Sea recommends for the Peninsula 500 in its series manual
• Skimmer: RSK DC 600 (water flow 1,500 lph — 396 gph, air flow 750 lph — 198 gph)
• Mechanical filtration: ReefMat 1200

You are free to build it differently, but this tells you exactly what class of hardware the manufacturer considers right for this water volume — a step up from the 350 on lighting, return pump and ReefMat alike.

Two things nobody plans for before delivery day

The ReefATO+ comes with the tank, but its top-off reservoir does not — Red Sea says so word for word in its series manual. You need a supply of RO water in the cabinet or beside it, and that is precisely what the ReefCan is for: a tall, narrow canister that fits wherever floor space is left.

And that water has to come from somewhere. On a 519 L system, water changes and automatic top-off draw RO water every single week. A 100 GPD RO/DI unit makes 380 L — 100 gal a day at home. It is not mandatory, but it pays for itself quickly once you stop hauling jugs.

Sump, ReefGate and the return outlets

The 106.6 L sump includes a mechanical filtration compartment — 225 micron filter socks and media cups — that lifts out completely. That is what makes the tank ReefMat-ready: you can move to a fleece roller filter later without modifying the sump. Red Sea advises keeping at least three sets of filter socks in rotation. The cabinet also reserves a chamber for a chiller and the rest of your hardware.

On the downflow, every G3 gets the ReefGate, a high-precision gate valve Red Sea developed for fine flow adjustment; properly set, it removes the noise of water flowing down to the sump, according to the manufacturer. On the return side, the Peninsula uses a dual-outlet return — which matters when you need to push flow across a 125 cm display fed from a single end.

Our advice

"My advice is always the same: get the biggest tank you can. It comes down to budget, yes — but the mistake I see most often is people buying slightly smaller because the difference doesn't seem that big. Then they regret it, they want to upgrade, and that is when it gets really expensive.

As for the weight, be careful. Generally speaking, it takes a well-built house — or bring in a contractor. That is not something we can guarantee: it really depends on your construction."

— Stéphane, Aquarium ReefSolution

Warranty

The Peninsula 500 G3 carries a 3-year warranty. Red Sea extends it to 5 years at no extra cost if you register the aquarium within 90 days of purchase — Canada is one of the countries where this extension is offered.

Why buy it from ReefSolution

Aquarium ReefSolution is an authorized Red Sea dealer based in Laval, Quebec. We ship large aquariums anywhere in Canada for a flat 100 $ rate, wherever you are. Freight moves LTL: the truck drops the crate outside, and delivery does not include carrying the tank into the house or setting it up — plan your labour for that day. And you are not just buying a box: a REEFER bought from us comes with our guidance — we build the best system for your expectations and your budget with you, from setup to everything after.

Frequently asked questions

How many gallons is the Peninsula 500 G3, exactly?

It depends which number you count. Red Sea publishes 137.1 US gal for the complete system, meaning display plus sump: 519 L. The display tank on its own holds 412 L (108.8 gal) — that is the volume some listings quote as 109 gallons. Both figures are correct; they simply measure different things.

Can my floor take the Peninsula 500 G3?

Red Sea states 761 kg (1,678 lb) for the complete system once filled. That is the number to give a contractor or an inspector if you are installing it on an upper floor of a wood-framed house. On a concrete slab the question does not arise.

How many people does it take to set up?

The glass tank alone weighs 121 kg (267 lb) according to Red Sea, and it has to be lifted onto the already-assembled cabinet. The manufacturer asks that you make sure you have the right number of people for the weight and size, and that the system is never moved once filled with water.

How much room does it take up?

Red Sea lists the Peninsula 500 G3 at 49.2", or 125 cm. Total system height including the cabinet is 160 cm (63") excluding the light unit, and the tank is 63.5 cm (25") wide. Allow 10 cm of clearance behind and 60 cm on one side for access to the back of the tank.

Does the Peninsula 500 G3 have a Euro-brace?

Yes — and it is new to this generation. Red Sea flags the Euro-brace on the Peninsula 500 as a new feature of the G3; the previous version was rimless. Within the current range, the only rimless Peninsula is the Peninsula 350 G3.

What return pump does the Peninsula 500 G3 need?

The Red Sea series manual recommends a ReefRun G2 8000 (4,100-8,300 lph — 1,080-2,200 gph) for this model — the same pump Red Sea installs on the MAX version of this tank. It is sold separately, as is its ReefRun Dual controller.

What comes in the box?

The 15 mm (0.6") ultra-clear glass display with its Euro-brace, the 106.6 L (28.2 gal) glass sump, the plumbing with the ReefGate valve, the cabinet and the ReefATO+ system. Lighting, circulation, return pump, skimmer, ReefMat and the ReefATO+ top-off reservoir are sold separately.

Can I put it against a wall?

Red Sea designs the Peninsula as a room divider with two long views and filtration at one end. Against a wall, you pay for the second viewing side without using it — a standard REEFER does the job better, for less.