Nyos Opus 440 G2 Aquarium and Cabinet

The NYOS ® OPUS ® G2 series are ready-to-use reef aquariums engineered to meet the highest standards of quality, functionality and aesthetics—so nothing distracts from the most important thing: the reef experience.

Key Features

• Hidden overflow: External downcomer embedded in the rear pane for a clean display and extra aquascaping space
• Three sides in ultra-clear glass with transparent silicone bonding for brilliant, lifelike colors
• Deep blue rear pane creating a realistic depth effect
• Two elegant base cabinet design lines to choose from: Slim-Line ® and Pro-Line ®
• High-quality, robust base cabinets with durable melamine resin coating
• Separate XL refill basin for convenient top-off
• Large, functionally designed technique sump with generous filter chamber
• Made in the EU with improved sustainability aspects

THE NYOS ® OPUS ® G2 AQUARIUM

The external drain shaft sits flush in the rear pane, eliminating a disturbing downcomer inside the tank, simplifying cleaning and maximizing space for rockwork and corals.

Windscreen and side panes in ultra-clear glass reduce green tint for vivid fish and coral coloration. The pool-basin design is free of side and cross braces, with clear, transparent silicone edges to keep the focus on the reef.

A precisely matched dark blue rear pane enhances the illusion of depth for a striking, natural underwater look.

Optimized proportions provide the room needed to create spectacular, stable reef structures.

THE NYOS ® OPUS ® G2 CABINET

Moisture-resistant EN 312 support plates, melamine-coated surfaces for scratch and impact resistance, and additional waterproof foam lining. Wood is sourced from verified legal origins (ISO 38200) and manufactured in FSC ® certified facilities with a low carbon footprint.

Increased cabinet height for easier access, push-to-open doors, and a timeless, minimalist aesthetic. Choose Slim-Line ® for space-saving minimalism, or Pro-Line ® for a cubic, statement look with extra storage, premium soft-close hinges, thicker panels, and a concealed sand edge.

Pro-Line highlights:

• Distinctive cubic design with expanded storage footprint
• Premium 125° soft-close hinges
• Thick, solid doors and concealed sand edge for a seamless look

Slim-Line highlights:

• Slim, space-saving footprint
• Clean, minimalist appearance
• Accessible entry into the OPUS G2 design language

THE NYOS ® OPUS ® G2 TECHNIQUE SUMP

Durable fixed piping installs easily and safely.

Accommodates skimmers, media reactors and algae filters at a constant water level of approx. 21 cm. Includes long-lasting nylon filter sock.

Fine-tune flow to minimize noise; emergency drain is standard for added security.

High-capacity top-off reservoir supports stable salinity over extended periods.

1) Settling chamber; 2) Filter sock; 3) Main filter chamber; 4) Optional sponge/bubble trap; 5) Return chamber with ATO sensor placement.

This premium reef-ready system blends display elegance, silent operation, and practical filtration—delivering a sustainable, high-performance foundation for thriving corals and fish.

ProLine

Aquarium:
Aquarium dimensions (L x W x H) 125 x 55 x 55 cm (35.4 x 21.7 x 20.9 in)
Volume aquarium (gross) 378L
Ultra clear glass Windscreen and side windows left and right
glass thickness 12mm
Hidden overflow (no downcomer in the aquarium) Yes

Cabinet (Pro Line):
Cabinet dimensions:  133,5 x 65,5 x 90 cm 
Colors available: White or basalt grey
Total height of aquarium with cabinet: 143 cm 
Height-adjustable feet: Yes
Sand edge and front silicone seal concealed: Yes
Hinges: Premium 125° with soft-close
Moisture-resistant wood boards in accordance with EN 312: Yes

Sump:
Sump dimensions: (L x W x H) 60 x 49,5 x 35 cm 
Sump water level: approx. 21cm 
Sump volume (gross) at a water level of 21cm : 62 liters 
Refill tank dimensions: (L x W x H) and volume (net) 17 x 42 x 50 cm, 22 liters 
Footprint (skimmer chamber): (L x W) 33 x 49,5 cm 
Footprint (return chamber): (L x W) 25 x 22 cm 

Emergency drain Yes
Recommended flow return pump 2.000 l/h (525 gph)
Adjustable valve on main drain Yes

SlimLine

Aquarium:
Aquarium dimensions (L x W x H) 125 x 55 x 55 cm (35.4 x 21.7 x 20.9 in)
Volume aquarium (gross) 378L
Ultra clear glass Windscreen and side windows left and right
glass thickness 12mm
Hidden overflow (no downcomer in the aquarium) Yes

Cabinet (Slim Line):
Cabinet Dimensions: 125 x 55 x 90 cm (49.2 x 21.7 x 35.4 in)
Colors available: White or basalt grey
Total height of aquarium with cabinet: 145 cm (4 ft 9 in)
Height-adjustable feet: No
Sand edge and front silicone seal concealed: No
Hinges: Standard
Moisture-resistant wood boards in accordance with EN 312: Yes

Sump:
Sump dimensions: (L x W x H) 60 x 49,5 x 35 cm (23.6 x 20 x 13.8 in)
Sump water level: approx. 21cm (8 in)
Sump volume (gross) at a water level of 21cm (8 in): 62 liters (16.4 gal)
Refill tank dimensions: (L x W x H) and volume (net) 17 x 42 x 50 cm, 22 liters (6.7 x 16.5 x 20 in, 6 gal)
Footprint (skimmer chamber): (L x W) 33 x 49,5 cm (13 x 20 in)
Footprint (return chamber): (L x W) 25 x 22 cm (8.9 x 8.7 in)

Emergency drain Yes
Recommended flow return pump 2.000 l/h (525 gph)
Adjustable valve on main drain Yes