Red Sea Reefer 300 G3+ - Black Cabinet

Red Sea Reefer 300 G3+ - Black Cabinet

The Red Sea Reefer 300 G3+ - Black Cabinet is a 300 litre (79.3 US gallon) reef-ready aquarium system combining a 246 litre (65 gallon) eurobraced ultra-clear glass display, a 54 litre (14.3 gallon) REEF-SPEC filtration sump, and a reinforced black marine-spec plywood cabinet. Its 90 cm (35.4 inch) length and 57.5 cm (22.6 inch) front-to-back depth provide room for substantial aquascaping while retaining a practical footprint for a custom marine reef aquarium.

The REEFER 300 G3+ adds eurobraced glass construction and integrated ReefControl Lite automation to Red Sea's established sump-based aquarium design. The included ReefControl ATO Module provides automatic freshwater replenishment and temperature monitoring, while the ReefGate precision valve, hydrodynamically optimized plumbing, curved return outlet, and ReefMat-ready sump handle the essential water-management functions. Lighting, return pump, protein skimmer, wavemakers, and additional monitoring equipment are selected separately.

Red Sea Reefer 300 G3+ Black Reef Aquarium Features

• 90 cm (35.4 inch) reef display: The longer aquarium provides room for separated rock structures, open swimming channels, and multiple coral placement areas that would be harder to accommodate in the compact REEFER 200 G3+.
• 57.5 cm (22.6 inch) aquascaping depth: The front-to-back dimension allows layered rockwork, sand areas, and coral colonies to be positioned at different distances from the viewing glass.
• Eurobraced ultra-clear glass: The G3+ generation introduces 10 mm (0.39 inch) jet-black perimeter eurobracing, reinforcing the aquarium structure and replacing the rimless design used on the previous 300 G3.
• 12 mm (0.47 inch) front viewing panel: Ultra-clear low-iron glass improves visibility of coral colours and marine fish while providing a thicker front panel than the smaller 200 G3+.
• Reinforced black cabinet: The marine-spec plywood stand supports the aquarium and features laminated panels, splash-resistant epoxy-painted doors, stainless steel hinges, and adjustable leveling feet.
• Customizable reef-ready platform: The system includes its aquarium infrastructure and ReefControl Lite automation while allowing major lighting, skimming, and circulation equipment to be selected individually.

ReefControl Lite and Integrated ATO Automation

The REEFER 300 G3+ includes the ReefControl Lite Controller and ReefControl ATO Module, providing automatic freshwater top-off and temperature monitoring as part of the standard aquarium package. This gives customers a connected starting point for water-level management without requiring the separate ReefATO+ controller used with the earlier G3 generation.

• ReefControl Lite Controller: Supports up to two compatible ReefSense digital probes or sensors and one additional 12V DC device, allowing selected monitoring functions to be added separately.
• Automatic top-off system: The ReefControl ATO Module uses a digital level sensor and dedicated DC pump to replenish evaporated freshwater and help maintain a consistent sump water level.
• Integrated temperature monitoring: The ATO level sensor incorporates a digital temperature sensor, providing temperature readings and notifications through the connected controller.
• ATO installation equipment: The module includes its level sensor, mounting components, pump, silicone tubing, tube holder, and siphon breaker.
• ReefBeat monitoring: Compatible equipment and sensor information can be accessed through Red Sea's ReefBeat ecosystem, with additional options available through ReefSense probes and ReefControl Power.
• Expansion limitations: ReefControl Lite supports fewer probe connections and auxiliary DC devices than ReefControl Pro, which is included with larger REEFER G3+ models. Additional probes and the Pro controller are not included with this standard 300 G3+ system.

ReefGate Quiet Drainage and Improved Return Plumbing

The REEFER 300 G3+ uses a central surface-skimming overflow with removable combs to collect water from the display. An enlarged rectangular inlet directs water into the downflow plumbing with reduced turbulence, while the ReefGate precision valve controls drainage to the sump for quiet, stable operation.

• Precision ReefGate valve: The adjustable valve allows small changes to the downflow rate, helping balance drainage with the selected return pump and maintain the intended water level inside the overflow.
• Hydrodynamic pipe connections: The compact G3+ design incorporates improved 45-degree pipe geometry and enlarged return connections to reduce unnecessary restrictions in the water path.
• Removable overflow combs: Surface-skimming sections can be removed for cleaning to prevent deposits and debris from restricting water movement into the overflow.
• Single curved 25 mm (approximately 1 inch) return: Filtered water returns to the aquarium through one curved outlet. The larger REEFER 425 G3+ and above introduce dual return outlets.
• Primary and secondary drainage: The overflow includes a regulated main downpipe and secondary bypass as part of its water-management arrangement.
• Factory-designed plumbing: The supplied drain and return pipework provides the core plumbing system, with optional metric and USA connection kits available for customized installations.

54 Litre REEF-SPEC Sump and ReefMat Filtration

The 54 litre (14.3 US gallon) sump provides separate mechanical filtration, adjustable protein skimming, and return circulation below the aquarium. Unlike the smaller 200 G3+, the 300 also supports an optional dedicated refugium divider, giving aquarists additional flexibility when planning their filtration equipment.

• 225-micron filter bag: One fine-mesh mechanical filter bag is included to collect suspended debris from water entering the sump.
• Included filter media cup: One media cup provides an additional filtration arrangement within the mechanical compartment.
• ReefMat-ready mechanical section: The removable filtration compartment is designed for conversion to compatible automatic fleece filtration without redesigning the standard plumbing.
• Optional ReefMat 500: Red Sea pairs the corresponding MAX 300 system with the ReefMat 500, providing an identified upgrade path for aquarists who prefer automated mechanical filtration.
• Adjustable skimmer chamber: Operating water depth can be set between 17 and 23 cm (6.7-9.1 inches) to accommodate compatible skimmers with different water-level requirements.
• Optional refugium divider: A compatible divider allows part of the sump to be configured as a dedicated refugium, providing another option for biological filtration and nutrient management.
• Bubble-stripping water path: Water passes through a bubble-management section before reaching the return pump chamber, helping prevent skimmer-generated bubbles from entering the display.

Choosing Equipment for the REEFER 300 G3+

The REEFER 300 G3+ is suited to aquarists planning a marine fish aquarium, soft coral or LPS display, or appropriately equipped mixed reef. Its 90 cm (35.4 inch) length provides room for more elaborate aquascaping than the 200, while the integrated controller and configurable sump give customers flexibility when selecting the remaining equipment.

• Recommended return pump: Red Sea specifies one ReefRun G2 4000 for the corresponding REEFER MAX 300 G3+ configuration. The pump is sold separately with this base system.
• Reef lighting: Red Sea uses two ReefLED G2 115 fixtures in the MAX 300 package. Customers building a custom system should select lighting appropriate for the 90 x 57.5 cm (35.4 x 22.6 inch) footprint and the planned coral requirements.
• Protein skimmer fitment: Choose a skimmer that fits the sump and operates correctly within the adjustable 17-23 cm (6.7-9.1 inch) water-depth range.
• Additional water movement: Dedicated wavemakers can provide circulation behind rockwork and around coral colonies beyond the flow delivered by the sump return.
• Freshwater reservoir planning: The included ATO module requires a suitable freshwater supply. Allow space for the top-off pump and reservoir when arranging filtration and other equipment.
• Optional refugium: Customers planning a dedicated refugium can use a compatible sump divider while considering the remaining space required for skimming and return equipment.
• 200 versus 300 G3+: The 300 adds 100 litres (approximately 26.4 US gallons) of total system volume, 30 cm (11.8 inches) of display length, and 12 litres (approximately 3.2 gallons) of sump capacity compared with the 200. Both models include ReefControl Lite and the ATO Module.

Red Sea Reefer 300 G3+ Black Specifications

• Total system water volume: 300 L / approximately 79.3 US gal.
• Display aquarium volume: 246 L / approximately 65 US gal.
• In-cabinet sump volume: 54 L / approximately 14.3 US gal.
• Display dimensions: 90 cm L x 57.5 cm W x 55 cm H / approximately 35.4 x 22.6 x 21.7 inches.
• Total system height including cabinet: 142 cm / approximately 55.9 inches.
• Front glass thickness: 12 mm / approximately 0.47 inches.
• Upper eurobracing: 10 mm / approximately 0.39 inches.
• Glass construction: Eurobraced ultra-clear glass bonded with high-quality euro-silicone.
• Cabinet: Black reinforced marine-spec plywood with stainless steel hinges, splash-resistant doors, and adjustable leveling feet.
• Return outlet: Single curved 25 mm connection.
• Mechanical filtration: Removable ReefMat-ready compartment with one 225-micron filter bag and one media cup.
• Skimmer chamber operating depth: Adjustable from 17-23 cm / approximately 6.7-9.1 inches.
• Refugium compatibility: Optional dedicated sump divider.
• Included controller: ReefControl Lite, supporting up to two compatible ReefSense probes or sensors and one additional 12V DC device.
• Included automatic top-off: ReefControl ATO Module with digital level and temperature sensor, DC pump, and installation accessories.
• Recommended return pump: ReefRun G2 4000, sold separately.
• Optional automatic filtration: ReefMat 500, sold separately.
• Manufacturer warranty: Standard 3 years, extendable to 5 years at no additional charge when registered within 90 days of purchase, subject to warranty terms.

Red Sea REEFER G3+ Series Video

Shipping Notes

• Red Sea aquariums are exempt from our free shipping policy.
• To avoid delays, please order your aquarium separately from other products. If purchasing additional items, place one order for the aquarium and a second order for your other products.
• Orders shipping to the Northwest Territories, Yukon, or Nunavut require a shipping quote. Please call for details.
• Red Sea aquariums are brought in and shipped on an as-ordered basis. The average turnaround time before shipping is approximately two business days, except where noted below.
• All shipments outside the Vancouver area are sent by trucking company with fully insured residential delivery and power tailgate service.
• Orders within British Columbia and, in some circumstances, Alberta may require an additional 5-10 business days for processing. Orders from Alberta and provinces farther east generally ship directly from the distributor in Ontario within two business days.
• For in-store pickup, select that option at checkout to avoid delivery charges. You will be notified when the aquarium arrives, usually within 5-10 business days.
• Red Sea MAX S Series aquariums are always special order and generally require 3-6 weeks before shipping.
• Freight delivery includes transporting the aquarium to the destination address and unloading it. The freight company is not responsible for carrying the aquarium inside the building.
• Freight charges have been substantially subsidized to help reduce the delivery cost of your new Red Sea aquarium.
• Rural, remote, and extended-service areas may require an additional shipping charge. We will contact you before shipping if an adjustment is necessary.

Directions

• Assemble and level the reinforced black cabinet according to the Red Sea installation instructions before positioning the aquarium.
• Install the REEF-SPEC sump, overflow, ReefGate valve, and supplied return plumbing with all seals and connectors correctly positioned.
• Mount the included ReefControl Lite Controller and connect the ATO level and temperature sensor and top-off pump according to Red Sea's instructions. Provide a suitable freshwater reservoir.
• Install a compatible return pump, skimmer, lighting, heating, and circulation equipment before operating the aquarium. Adjust the skimmer chamber water level to the requirements of the chosen protein skimmer.
• Follow the manufacturer's initial-fill procedure and inspect plumbing connections for leaks.
• Adjust the ReefGate valve in small increments, allowing several minutes for the overflow operating level to stabilize after each adjustment.
• Perform a power-out test to ensure the sump can accommodate water draining from the display when the return pump stops.
• Clean the mechanical filter bag, media cup, overflow combs, return outlet, and ATO level sensor as required during routine maintenance.
• Register the aquarium with Red Sea within 90 days of purchase to qualify for the extended manufacturer warranty.

What's Included

• REEFER 300 G3+ eurobraced ultra-clear glass aquarium
• Black reinforced marine-spec plywood cabinet with adjustable leveling feet and stainless steel hinges
• 54 litre REEF-SPEC sump with adjustable-height skimmer chamber and removable ReefMat-ready mechanical filtration compartment
• One 225-micron mechanical filter bag
• One filter media cup
• Downflow and return plumbing with ReefGate precision valve
• Central overflow with removable surface-skimming combs
• Single curved 25 mm return outlet
• ReefControl Lite Controller
• ReefControl ATO Module with digital level and temperature sensor, ATO pump, and installation accessories