OPUS 300


OPUS 300 Tank

With Nyos® OPUS®, we created a ready-to-use reef aquarium that will satisfy the highest demands in terms of quality, functionality and aesthetics. Attention has also been placed on important details, which make the difference. Through the minimalistic design, the aquarium itself melts into the background. In this way, nothing detracts from the most important aspect: The reef experience.

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Clear glass edges

In order to detract as little as possible from the reef experience, only transparent silicone is used in the display aquarium.

Three sides with ultra-clear glass for brilliant colors

The front pane and both side panes are each produced from ultra-clear glass. In comparison to conventional glass, ultra-clear glass exhibits a significantly weaker green tint, so that the colors of the fish and corals appear much more richly contrasting and lively.

Hidden Overflow

The Nyos® OPUS® is equipped with an external over flow box recessed in the back pane. With no interfering overflow box inside the aquarium, additional spa ce is available for aquascaping. It is also simple and straightforward to keep the back pane clean.

Recessed aquarium

The aquarium is recessed in the cabinet. This conceals the often unsightly bottom silicone seam, as well as the sand edge of the aquarium. With this, the view of the reef is entirely unimpeded.

Deep blue lacquered back pane for realistic depth effect

The back pane of the aquarium is finished in a precisely tailored dark shade of blue. When the aquarium lighting is switched on, this creates the perfect illusion of a realistic underwater world with depth effect.

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Cubic cabinet design

The cubic cabinet design delivers the OPUS®-typical, distinctive look and perfectly sets the reef as the central feature.

Seamless finish

Within the framework of pre-assembly in the factory, all external gaps and seams in the cabinet are sealed. This results in a perfectly seamless finish, as if cast from a single piece.

Full-surface all-round lacquered finish

The entire surface of the Nyos® OPUS® cabinet is finished internally and externally with multiple layers of lacquer. This provides additional internal protection against salt water and ensures the cabinet is particularly durable. The exterior exhibits the OPUS®-typical, perfectly seamless finish in a matt look.

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High-quality workmanship
down to the last detail



Sophisticated design of the sump for multi-stage filtration

The sump is equipped with 6 chambers. The return water initially flows into a settling chamber, before being fed through a fine filter (filter bag). This is followed by a forced-flow, free filter chamber. It is possible to introduce filter media such as active carbon, zeolite or similar in this chamber if necessary. The large main chamber exhibits a constant water level of approx. 21cm (8.5 in) and is therefore ideal for Nyos® QUANTUM® skimmers. A bubble trap is installed in front of the return chamber, in order to reduce any micro-bubbles that may arise.

Space-saving integrated auto top off system

An integrated mechanical auto top off system ensures compensation for water lost through evaporation. The refill tank optimally utilises the free space in the area of the return chamber.


  1. Settling chamber
  2. Filter bag
  3. Free filter chamber
  4. Main Chamber
  5. Bubble trap
  6. Return chamber
  7. Refill tank

Technical Data

Technical Drawing

What’s in the box

  • ·Aquarium with external overflow shaft and ultra-clear glass on three sides
  • ·Cabinet fully assembled, optionally in basalt grey or white
  • ·Pre-glued PVC plumbing
  • ·Sump including refill tank and mechanical auto top off system
OPUS® Tank Nyos® OPUS® 300
Aquarium dimensions (L x W x H) 90 x 55 x 53 cm (35.4 x 21.7 x 20.9 in)
Aquarium volume (gross) 262 l (69 gal)
Ultra-clear glass aquarium Front pane and both side panes
Glass thickness 10 mm (0.4 in)
OPUS® Cabinet
Cabinet dimensions (L x W x H) 98 x 66 x 76 cm (38.6 x 26.0 x 29.9 in)
Available cabinet colors White or basalt grey
Cabinet lacquered on all sides Yes
OPUS® Sump
Sump dimensions (L x W x H) 55 x 38 x 38 cm (21.7 x 15.0 x 15.0 in)
Sump water level ca. 21 cm (8.5 in)
Sump volume with 21cm water level (gross) 44 l (11.6 gal)
Integrated auto top off system Yes
Refill tank volume 6,5 l (1.7 gal)
Size of medium filter chamber (skimmer chamber) (L x W x H) 24 x 38 cm (9.4 x 15.0 in)
Size of return chamber/chamber for return pump (L x W xH) 12 x 38 cm (4.7 x 15.0 in)
Total height (cabinet plus tank) 127 cm (50 in)
Emergency overflow Yes
Recommended return pump capacity 2.000 l/h (525 gph)
Maximum overflow capacity 5.000 l/h (1320 gph)
Adjustable return Yes
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The Nyos® OPUS® 300 Reef Aquarium - Official Teaser

The Nyos® OPUS® 300 Aquarium - Episode 1 - Unboxing and setup

The Nyos® OPUS® 300 Aquarium - Episode 2 - Installing the hardware

The Nyos® OPUS® 300 Aquarium - Episode 3 - Water, Sand & Aquascape

The Nyos® OPUS® 300 Aquarium - Episode 4 - Water Parameters, Invertebrates, Corals & Fish