Red Sea Reefer 525 G3 - Black Cabinet

The Red Sea Reefer 525 G3 - Black Cabinet is a premium 540 litre / 142.7 gallon reef-ready aquarium and cabinet system built for aquarists who want a large euro-braced Red Sea REEFER G3 display with a clean black marine-spec cabinet and full freedom to choose their own reef equipment.

This base REEFER G3 system gives you the professional aquarium, cabinet, sump, plumbing, overflow, ReefGate drain control, ReefMat-ready filtration layout, and integrated ReefATO+ foundation without bundling lighting, return pump, skimmer, heater, wavemakers, rock, sand, salt, or livestock. It is ideal for hobbyists who want the structure and reliability of Red Sea’s G3 platform while selecting the exact hardware package that fits their coral goals, livestock plan, automation preference, and budget.

Red Sea REEFER 525 G3 Black Reef System

• Large 150 cm reef-ready platform: The REEFER 525 G3 moves into a true large-display footprint with enough length for more natural aquascapes, broader coral spacing, and improved fish movement.
• 540 litre total system volume: The added water volume gives reef keepers more stability, more livestock planning flexibility, and a stronger foundation for long-term coral growth than smaller reef systems.
• Black cabinet finish: The black marine-spec cabinet creates a bold, modern look that visually frames the reef and helps equipment, shadows, and cabinet space recede.
• Base-system flexibility: Return pump, lighting, skimmer, heater, wavemakers, dosing equipment, and automation hardware are selected separately so the system can be built around the reef you actually want to keep.
• Euro-braced G3 construction: The 525 is part of Red Sea’s larger euro-braced REEFER G3 range, adding structural reinforcement while preserving a clean premium display profile.
• Red Sea ecosystem ready: The aquarium is a strong platform for optional ReefRun pumps, ReefLED lighting, REEFER skimmers, ReefMat filtration, ReefWave pumps, ReefDose, and ReefBeat-connected devices.

150 cm Euro-Braced Ultra-Clear Display

• 423 litre display volume: The main aquarium gives substantial room for coral colonies, reef-safe fish, open swimming areas, and a more mature aquascape.
• 150 x 60 x 55 cm footprint: The 150 cm length and 60 cm depth create a strong aquascaping canvas for islands, ridges, open channels, cave structures, and layered coral placement.
• 15 mm glass specification: The REEFER 525 G3 is listed with 15 mm front, side, bottom, and back glass for a reinforced large-display build.
• Ultra-clear viewing panels: Low-iron glass improves clarity and reduces tint so coral colour, fish movement, and reef lighting appear cleaner through the panels.
• Euro-braced top design: The bracing supports the larger aquarium format while keeping the display clean and professional looking.
• Cabinet-contained equipment: The sump and support equipment sit below the tank so the display remains focused on rockwork, coral, and livestock rather than visible hardware.

G3 Flow System and ReefGate Quiet Control

• Hydrodynamically improved plumbing: REEFER G3 systems use redesigned water-management architecture for better circulation efficiency and more effective movement through the sump.
• Quiet rectangular downflow inlet: The enlarged drain inlet is designed to reduce turbulence and help the system run more quietly when properly adjusted.
• ReefGate precision valve: The high-precision downflow valve gives fine control over the drain line so the overflow and sump water level can be tuned for near-silent operation.
• Surface-skimming overflow: The central overflow includes a removable surface skimmer to draw surface film and floating debris into the filtration path.
• Curved dual return outlets: Improved return nozzles help distribute water back into the display more effectively than straight returns.
• Pre-assembled plumbing: Factory-designed downflow and return plumbing makes installation cleaner and more predictable than a fully custom plumbing build.

REEF-SPEC Sump and ReefATO+ Automation

• 116 litre sump capacity: The large in-cabinet sump provides dedicated space for mechanical filtration, return equipment, skimmer selection, media, probes, dosing lines, and optional filtration upgrades.
• ReefMat-ready mechanical section: The sump includes a removable mechanical filtration compartment with micron socks and media cups and is designed for optional Red Sea ReefMat installation.
• Integrated ReefATO+: The included smart top-off system helps stabilize water level and salinity while adding temperature monitoring and leak detection.
• Flexible filtration planning: The sump can support carbon, reactors, refugium-style nutrient export, dosing equipment, monitoring probes, and advanced reef filtration equipment depending on the build.
• Service-friendly layout: Keeping filtration equipment inside the cabinet gives better access for skimmer cleaning, filter maintenance, pump service, and future upgrades.
• Large-system stability: The 525 format offers enough water volume and sump capacity to support a carefully planned mixed reef or coral-focused display with the right equipment choices.

Black Marine-Spec Cabinet with Aluminum Supports

• Marine-spec plywood cabinet: The cabinet is designed for aquarium use with moisture-resistant construction, leveling feet, stainless steel hinges, and a clean furniture-style finish.
• Front aluminum supports: Red Sea’s 525 models and above use front aluminum cabinet supports for additional rigidity across the larger span.
• Clean black finish: The black cabinet creates a strong contrast against bright reef lighting and helps the aquarium feel visually grounded.
• Equipment concealment: The cabinet keeps sump equipment, plumbing, ATO hardware, and future accessories hidden below the display.
• Better long-term service access: The larger cabinet footprint gives more room for equipment planning than smaller compact systems.
• Display-ready appearance: The finished black stand makes the aquarium suitable for living rooms, offices, showrooms, and dedicated reef spaces.

Red Sea Reefer 525 G3 Black Specifications

• Total system volume: 540 L / 142.7 gal.
• Display volume: 423 L / 111.7 gal.
• Sump volume: 116 L / 30.6 gal.
• Display dimensions: 150 cm L x 60 cm W x 55 cm H / approx. 59.1 x 23.6 x 21.7 in.
• Total height with cabinet: 142 cm / approx. 55.9 in.
• Glass thickness: 15 mm front glass, 15 mm side glass, 15 mm bottom glass, and 15 mm back glass.
• Display format: Euro-braced ultra-clear glass aquarium.
• Cabinet: Black marine-spec plywood cabinet with leveling feet and front aluminum supports.
• Filtration: REEF-SPEC sump with mechanical chamber, micron socks, media cups, ReefMat-ready layout, and ReefATO+.
• Recommended return pump: Red Sea ReefRun G2 8000, sold separately.
• Lighting: Sold separately and should be selected for full 150 cm x 60 cm reef coverage.

Application Notes for the REEFER 525 G3

• Best use: Ideal for larger mixed reefs, soft coral systems, LPS displays, SPS-capable builds with proper flow and lighting, and custom reef aquariums needing a serious sump-based foundation.
• Equipment planning: Add a suitable return pump, lighting, protein skimmer, heater, wavemakers, and testing equipment before cycling the aquarium.
• Lighting planning: Choose reef lighting based on coral type, desired spread, mounting style, PAR goals, and full front-to-back coverage.
• Flow planning: The return plumbing handles sump turnover, but dedicated wavemakers are still needed for reef circulation across the full 150 cm display.
• Filtration upgrade path: The ReefMat-ready sump is well suited for customers planning automatic fleece-roll mechanical filtration.
• Not included: Lighting, return pump, protein skimmer, heater, wavemakers, livestock, rock, sand, salt, optional ReefMat, dosing equipment, and test kits are sold separately unless otherwise stated.

Red Sea REEFER G3 Series Video

Setup and Installation Notes

• Assemble and level the cabinet: Build the black cabinet according to Red Sea’s instructions and confirm the system is level before placing the aquarium.
• Plan equipment before filling: Select the return pump, skimmer, heater, lighting, wavemakers, and optional automation before adding water, rock, or livestock.
• Install plumbing carefully: Confirm the overflow, downflow, ReefGate valve, return plumbing, sump, and ReefATO+ components are correctly installed.
• Leak test with freshwater: Run the system with freshwater before final saltwater setup to confirm plumbing seals, sump operation, and return flow.
• Tune the ReefGate gradually: Make small adjustments until the overflow and sump run quietly with a stable water level.
• Use RO/DI water: RO/DI water is recommended for saltwater mixing and evaporation top-off to support stable reef chemistry.
• Cycle before stocking: Establish biological filtration before adding fish or corals, then stock gradually to maintain stability.

What’s Included

• Euro-braced ultra-clear glass aquarium
• Black marine-spec plywood cabinet with leveling feet and front aluminum supports
• REEF-SPEC sump with mechanical chamber, micron socks, and media cups
• Pre-assembled downflow and return plumbing with ReefGate precision valve
• Central overflow with removable surface skimmer
• Curved dual return nozzles
• Integrated ReefATO+ sensors and controller

Shipping Notes

• This item is exempt from our free shipping policy.
• To avoid delays, please order Red Sea aquariums by themselves. If you are wishing to order multiple things, please place two separate orders: one for the aquarium and one for the rest of your products.
• Please call for a shipping quote if ordering from NWT, YK, or NUN.
• All Red Sea aquariums are brought in and shipped out on an as-ordered basis. The average turn-around time to ship an aquarium to you is two business days, except where noted below.
• All shipments outside of the Vancouver area are shipped via trucking company with residential and power tailgate delivery, and are fully insured.
• Tanks ordered within BC and, in some circumstances, Alberta may take an extra 5-10 business days to process. Systems ordered from Alberta and east of there usually ship within two business days direct from the distributor in Ontario.
• If you are ordering for pick-up from our store, please select in-store pickup to avoid delivery charges. You will be notified when the tank arrives, usually within 5-10 business days.
• Red Sea Max S Series aquariums are always special order and will take from 3-6 weeks to ship.
• Please note the freight company is only responsible for getting the aquarium to the destination address and off-loading it. They are not responsible for carrying it inside.
• All freight charges have been greatly subsidized to help you get up and running with your new Red Sea system.