Nyos Opus 300 grey


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.


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.



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.



Sophisticated design of the sump for multistage 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.

Spacesaving 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

Product information

Opus TankNyos Opus 300
Aquarium dimensions (L x B x H)                  990 x 55 x 33 cm (35.4 x 21.7 x 20.9 in)
Aquarium volume (gross)262 l
Ultra-clear glass aquariumFront pane and both side panes
Glass thickness                                     10 mm (0.4 in)

Opus Cabinet 
Cabinet dimensions (L x B 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 B x H)55 x 38 x 38 cm (21.7 x 15.0 x 15.0 in)
Sump water levelca. 21cm (8.5 in)
Sump volume with 21 cm water level (gross)44 l (11.6 gal)
Integrated auto top off systemYes
Refil tank volume6,5 l (1.7 gal)
Size of medium filterchamber (skimmer chamber) (L x W x H)24 x 38 cm (9.4 x 15.0 in)
Size of retunr chamber/chamber for retunr pump (L x W x H)12 x 38 cm (4.7 x 15.0 in)                                              

Total height127 cm (50 in)                                           
Emergencey overflowYes
Recomemended return pump capacity               2.000 l/h (525 gph)
Maximum overflow capacity5.000 l/h (1320 gph)
Adjustable returnYes

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 

Attention: The tank will be delivered free to curbside. The tank and the cabinet is on one pallet, so we recommend to have two persons available on the day when the tank arrives!

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