Red Sea REEFER 170 G3 — 43.6 gal Rimless Reef Aquarium 24 in with ReefATO+

Red Sea REEFER 170 G3 — the smallest REEFER with a true sump

The REEFER 170 G3 is the entry point to the series: a 24 in (60 cm) rimless display holding 43.6 US gallons of total volume (165 L), on a cabinet that hides a 37 L REEF-SPEC sump — the smallest Red Sea format to offer real under-tank filtration instead of a rear compartment. It takes the place of the MAX E-170 in the brand's lineup, with the full G3 architecture: silent downflow, ReefGate valve, ReefMat-ready sump and the ReefATO+ smart top-off included. The same sump architecture runs on the 525 G3 at our store — we filmed a whole video series on it (in French, on the French side of this page).

Official REEFER 170 G3 specifications

• Total system volume: 165 L / 43.6 US gal
• Display volume: 128 L
• Sump volume: 37 L
• Display tank: 24 in (60 cm) long × 50 cm wide × 51 cm tall
• Total system height: 137 cm
• Ultra-clear glass: 10 mm front, 12 mm sides, 10 mm bottom, 8 mm back
• Frame: rimless, smooth beveled edges
• Operating weight: 275 kg / 607 lb
• Glass aquarium alone: 35 kg / 77 lb

Source: Red Sea's official REEFER G3 Models & Specs table and the series manual.

Floor load, clearances and placement

At 607 lb (275 kg) running, the 170 sits comfortably on most residential floors — and its 77 lb (35 kg) glass tank lifts onto the cabinet with two people. Red Sea puts the cabinet top at 86 cm (34 in) from the floor and asks for 10 cm (4 in) of clearance behind the tank for cables, plus 60 cm (24 in) free on one side for rear access. A stable room at 22°C (72°F), away from direct sun and heat sources, completes the setup.

Rimless glass, ReefGate and G3 piping

Like every straight REEFER up to the 350, the 170 G3 is rimless: ultra-clear, bevel-edged glass with no frame or brace for an open view of the reef. The redesigned G3 piping delivers, per Red Sea, up to 50% more water circulation than the previous generation, and the ReefGate high-precision gate valve fine-tunes the drain. The marine-spec plywood cabinet carries epoxy doors, stainless hinges and leveling feet.

What's in the box — and the official MAX configuration

Included: the glass tank, the self-assembly cabinet, the ReefMat-ready REEF-SPEC sump with micron filter bags and media cups, the glue-free internal piping kit, and the ReefATO+ smart top-off with temperature probe and leak detector. Lighting, return pump, protein skimmer, wavemaker and the top-off reservoir are chosen separately.

Red Sea's published MAX configuration for the 170: 1 × ReefLED G2 115 light, 1 × ReefWave 25 gyre pump, one ReefRun G2 4000 return pump — the model the series manual recommends — the RSK 300 DC skimmer and the ReefMat 250 roller filter.

Plan for these as well

The ReefATO+ reservoir never ships with any G3: the ReefCan fits inside the cabinet and connects directly. For RO water, an AquaticLife 100 GPD RO/DI unit easily covers a system this size, and since the tank is open-topped, a Net Cover screen cut to size protects jumping fish.

Sump and plumbing

The removable surface skimmer feeds the enlarged rectangular downflow inlet, which cuts turbulence and flow noise. The ReefGate valve locks the overflow-box level between the two intakes — the one adjustment that silences the drain. Inside the sump: 225-micron filter bags (Red Sea suggests three sets), an adjustable-height skimmer chamber, a bubble trap ahead of the pump section, and a constant level held by the ReefATO+.

Our advice

"The 170 is the smallest Red Sea tank that comes with a true sump. It's for people with limited space who are still fairly advanced: they want all the filtration below, inside the cabinet — the top-off, the sump, it's a real advantage. It's the perfect tank for an apartment or a condo: not too big, easy to set up, it doesn't take much room, and you keep all the REEFER quality and the equipment ecosystem that goes with it."

"The mistake people often make with small aquariums: they buy small because they lack space, then they want the fish from the big tanks. I advise against that — tangs in a small aquarium like this simply don't work long term. There are fish made for small tanks: they do much better there and stay less aggressive. A nice little rockscape, a small ecosystem with little fish wandering through the invertebrates — that's balanced. Big fish in a small aquarium just don't go together: it's unbalanced." — Stéphane, Aquarium ReefSolution

3-year warranty, extendable to 5 years

The base warranty covers the system for 3 years. Original purchasers who register their aquarium with Red Sea within 90 days receive 2 extra years at no charge on the structural integrity of the glass and cabinet — Canada qualifies.

Why buy your REEFER 170 from ReefSolution

A first sumped system succeeds with people behind it. When you buy an aquarium from us, we call you: we go over your questions, what your setup is missing, and we show you how — before and after the sale, with thirty years in the trade and videos filmed on our own systems. Secure delivery across Canada at a flat $100 rate.

FAQ — Red Sea REEFER 170 G3

What replaces the Red Sea MAX E-170?

The MAX E-170 is no longer produced. In Red Sea's current lineup, the 24-inch format with a sump is the REEFER 170 G3 — the same compact footprint, now with the full G3 architecture: ReefGate, ReefMat-ready sump and ReefATO+ included. The lighting, built into the MAX E, is chosen separately here — which lets you pick exactly the light you want.

Does the REEFER 170 G3 come with a skimmer and return pump?

No. Red Sea's official spec table lists the main pump, protein skimmer, wavemaker and lighting as not included. The series manual recommends the ReefRun G2 4000, and Red Sea's MAX configuration pairs the RSK 300 DC skimmer and the ReefMat 250 with this model.

What fish can live in a 43-gallon reef tank?

Fish made for smaller volumes — they do better and stay less aggressive. Large swimmers like tangs don't suit this format long term. A small rockscape with little fish and invertebrates makes a balanced ecosystem — call us and we'll build the stocking list together.