Red Sea Reefer Peninsula S-700 G3 — Euro-Brace 186 gal Room Divider Reef Aquarium

The Red Sea Reefer Peninsula S-700 G3 is a 705 L (186.2 US gal) peninsula reef tank — the S-series format of the Peninsula family. The display tank measures 151 cm long — 59.4" per Red Sea — by 68 cm wide and 65 cm tall, with all filtration grouped at one end: set against the end of a wall, it divides the room and shows off the reef from both long sides. It is the first Peninsula in the line built with 19 mm glass, and it carries the aluminum super-structure and slide-out control panel that Red Sea reserves for its S series.

In this video shot at our store, we walk through the ReefATO+ and how it keeps the water level rock-stable. The Peninsula S-700 ships with this exact system as standard — what you see here is what will run inside your cabinet.

Official Peninsula S-700 G3 numbers

Every value below comes from Red Sea's published specification table and configurator.

• Total system water volume: 705 L — 186.2 US gal
• Display tank water volume: 568 L — 150.1 US gal
• In-cabinet sump water volume: 136.7 L — 36.1 US gal
• Display tank length: 151 cm — 59.4"
• Display tank width: 68 cm — 26.8" — display tank height: 65 cm — 25.6" (excluding light unit)
• Total system height: 165 cm — 65" (excluding light unit)
• Ultra-clear low-iron glass, front, sides, bottom and back: 19 mm — 0.75"
• Rim type: jet-black Euro brace + bottom brace
• Hydrodynamic piping with the high-precision ReefGate valve — new on G3
• Cabinet: aluminum super-structure, replaceable marine-spec plywood exterior panels, hidden adjustable feet
• Slide-out control panel 60: included

Weight, flooring and space planning

These figures come from the REEFER G3 series manual. No product page shows them — yet they decide whether this saltwater aquarium can live in your home, especially at this size.

• Total system weight once filled: 1,087 kg — 2,397 lb
• Glass tank alone, to be lifted onto the cabinet: 206 kg — 454 lb
• Cabinet top height: 100 cm — 40", versus 86 cm (34") on straight REEFERs
• Clearance behind the tank: 10 cm — 4" minimum
• Recommended clearance on one side: 60 cm — 24" for rear access
• Recommended room temperature: 22°C — 72°F

At 2,397 lb filled, floor structure stops being a detail: that is the number to hand your contractor or an engineer if the reef tank is going on an upper floor of a wood-framed house. On a basement concrete slab, there is nothing to check. And a 454 lb glass tank is not a two-person lift — book your crew before installation day, because the system must never be moved once filled.

The Euro brace and the 19 mm glass

Unlike the Peninsula 350 — the only rimless model in the family — the S-700 gets the jet-black top and bottom bracing Red Sea fits to its Peninsula 500, S-700 and S-950. The manufacturer describes it as an elegant frame built into the aquarium glass for extra strength, while keeping the view wide open on both long panes. Together with 19 mm ultra-clear glass on every face, that bracing is what lets Red Sea stretch this format to 151 cm and 705 L.

The top stays open — nothing stops a startled fish from jumping. Red Sea makes a frame-mounted, trim-to-size Net Cover for exactly this kind of open tank: order it with the aquarium if jumpy species are in your plans.

The slide-out control panel — an S-series exclusive

The S-700 ships with the slide-out control panel 60, which Red Sea reserves for its S and Peninsula S series. It is a panel on rails inside the cabinet that pulls fully out so you can mount, wire and service controllers, power bars and ReefBeat modules — then slides back out of sight. On a system running a skimmer, a ReefMat, dosers and connected lighting, it is the difference between an organized cabinet and a nest of cables.

What is included — and what is not

The Peninsula S-700 G3 is sold as a foundation to equip, not a turnkey system. Red Sea supplies the tank, the cabinet, the 136.7 L glass sump, the complete piping with ReefGate, the slide-out panel and the ReefATO+ — its smart top-off system that stabilizes water volume and salinity, monitors temperature and detects leaks.

Not included: lighting, return pump, protein skimmer, wavemakers and automatic mechanical filtration. Red Sea sells this same tank as a fully equipped MAX version and publishes exactly what it installs — the best reference there is for sizing your own build:

• Lighting: 3 x ReefLED G2 170
• Flow: 2 x ReefWave 45 (15,000 lph — 3,963 gph)
• Return pump: 1 x ReefRun G2 12000 (5,000-12,000 lph — 1,300-3,200 gph) — also the model the series manual recommends for the PS-700
• Skimmer: RSK 900 DC (water flow 2,000 lph — 528 gph, air flow 900 lph — 238 gph)
• Mechanical filtration: ReefMat 1200

You are free to build differently — but this list tells you the calibre of equipment the manufacturer itself considers right for 705 L.

Two things nobody plans for before delivery

The ReefATO+ is included, but its top-off water reservoir is not — Red Sea states it word for word in the series manual. You need an RO water reserve near the cabinet, and that is the job of the ReefCan, a vertical container designed to slide into whatever space is left.

That water also has to come from somewhere. A 705 L saltwater system consumes RO water every week between top-off and water changes — at this scale, hauling jugs gets old fast. An RO/DI unit rated 100 GPD makes 380 L — 100 gal a day right at home.

The sump, the ReefGate and the side returns

The 136.7 L sump includes a mechanical filtration compartment — 225-micron filter socks and media cups — that removes entirely. That is what makes the tank ReefMat-ready: the sock tray and divider wall come out to receive a roller filter, no modifications needed. Red Sea recommends keeping at least three sets of socks in rotation. An optional refugium wall can split the chamber into two sections, and a bubble-trap labyrinth guards the pump compartment inlet.

On the drain, every G3 gets the ReefGate, Red Sea's high-precision gate valve for fine flow tuning: the manufacturer describes a down-flow system whose water noise disappears once the valve is properly set, pairing a regulated main downpipe with an emergency bypass.

On the return side, the Peninsula runs piping of its own: two curved, side-mounted outlets shaped to push current all the way down the tank — a real challenge across 151 cm. One practical detail: the cabinet doors mount on the left or the right, whichever side gives you the best sump access once the tank is in place.

Our advice

"With the Peninsula S-700 you're stepping into the major leagues: it's among the biggest aquariums we install, and it's still a peninsula — a true room divider. It's a collector's piece, stunning in a living room. When people walk into your home, the aquarium is what they look at — everything else fades. Young or old, everyone stops in front of it. A reef tank this size becomes the focal point of the whole room; it draws everyone's attention."

— Stéphane, Aquarium ReefSolution

Warranty

The Peninsula S-700 G3 is covered by a 3-year warranty on the glass aquarium and cabinet. Red Sea extends it to 5 years at no charge if you register the system within 90 days of purchase — Canada is on the list of eligible countries.

Why buy from ReefSolution

Aquarium ReefSolution is an authorized Red Sea dealer in Laval. We ship large aquariums anywhere in Canada at a flat 100$ rate, whatever the province. Freight moves LTL — the truck drops the crate outside, and that is all: carrying the aquarium in and setting it up are not included, so have your labour on site the day it arrives. And a system of this calibre is not an anonymous box. Buying a system is easy; running it long term is another story. Buy your REEFER from us and we support you in building the best system for your expectations and your budget — equipment choices, setup, start-up and everything after. Shopping for a more compact peninsula aquarium? See the Reefer Peninsula 500 G3 (49.2") or the Reefer Peninsula 350 G3 (37.8", the only rimless one).

Frequently asked questions

How many gallons is the Peninsula S-700 G3?

Red Sea publishes 186.2 US gal for the complete system — tank plus sump, or 705 L. The display tank alone holds 568 L (150.1 gal) and the in-cabinet sump 136.7 L (36.1 gal). When two listings quote different gallons, check which of the two volumes they are measuring.

Can my floor support the Peninsula S-700 G3?

Red Sea rates the complete filled system at 1,087 kg (2,397 lb). On an upper floor of a wood-framed house, that is the number to give a contractor or engineer before ordering. On a basement concrete slab, there is nothing to calculate.

How many people does the install take?

The glass tank alone weighs 206 kg (454 lb) per Red Sea, and it gets lifted onto the assembled cabinet. The manufacturer asks you to gather enough physically capable people for the weight and size — and never to move the system once it holds water.

How much room does it take?

The display tank is 59.4" (151 cm) long by 68 cm wide, and the system stands 165 cm tall without lighting. Plan 10 cm of clearance behind and 60 cm on one side for maintenance. The cabinet top sits at 100 cm — 14 cm higher than a straight REEFER.

Does the Peninsula S-700 have a Euro brace?

Yes. The S-700 carries the jet-black top and bottom bracing, like the Peninsula 500 and S-950. The only rimless Peninsula G3 is the 350.

What comes in the box?

The 19 mm (0.75") ultra-clear glass tank, the 136.7 L (36.1 gal) glass sump, the piping with the ReefGate valve, the aluminum super-structure cabinet, the slide-out control panel 60 and the ReefATO+ system. Lighting, wavemakers, return pump, skimmer, ReefMat and the ReefATO+ top-off reservoir are sold separately.

What return pump does the Peninsula S-700 G3 need?

The Red Sea series manual recommends one ReefRun G2 12000 (5,000-12,000 lph — 1,300-3,200 gph) for the PS-700 — the same pump Red Sea installs on the MAX version of this model. It is not included with the system.