Keeping fish in the Nano Marinus Cube

The overwhelming majority of coral fish, including those that remain small, are active swimmers and thus not suitable for keeping in a Nano Cube. The popular clownfish, which rose to prominence in the film "Find Nemo" is a typical example. It requires more space than a small aquarium is able to offer – at least 100 litres. Gobies are a different story. They swim only extremely short stretches, spending most of their time observing their surroundings from a coral or rock. The smallest gobies measure barely more than 20 mm in length. The radius within which they move in their natural environment is also smaller than the base area of a Nano Cube with a volume of 30 l.

These little fish feel at home in such an aquarium and do not feel constrained within the bounds of this habitat. On the contrary – they suffer from the hectic pace of life in a conventionally sized reef aquaria with numerous large, highly active fish darting around and hide themselves away with barely a chance of survival. A 30 or 60 l Nano Cube is much more suitable for them. The Nano Cubes have not been developed primarily as a habitat for fish, however, but rather for corals and other invertebrates - creatures which require little care and technical support. The aim is to bring a small cross-section of life from a natural reef into your living room in the form of a small-scale habitat which will retain its biological stability in the long term with a minimum of care.

Fish with a high metabolic rate require larger amounts of feed. This means that a more extensive range of technical equipment, such as a skimmer, is necessary in order to maintain the water quality. As a rule, an invertebrate aquarium containing corals and shrimps is biologically much less complicated than an aquarium with fish – but no less fascinating.

With this in mind, you should run your Nano Cube for the first few months without any fish. Wait until it has become biologically stable before adding fish – two members of a nano fish variety with the Cube 30, for example.

Who's taboo?
No creatures which are unable to survive in the long term under the prevailing conditions in a Nano Cube should ever be kept in such an aquarium. It is important to heed the needs of the creatures in your Cube at all times. This means that the Nano Cube is not suitable for particularly active swimmers or for young fish which will be too large for these aquaria when they reach adulthood. Species with specialised nutritional needs or which require extremely constant conditions will also fail to thrive in nano aquaria in the long term. All the creatures in the aquarium, such as shrimps or crabs, should be as peaceable as possible to ensure their easy integration.

Fish varieties for NanoCubes

The white-lined coral goby (Gobiodon albofasciatus) grows to a length of only 25 mm and requires little space. It spends most of its time sitting on a coral or a mushroom polyp. Numerous other Gobiodon varieties are ideal for keeping in a Nano Cube. The Trimma genus comprises a wealth of magnificently coloured tiny fishes, none of which are very active swimmers. The photograph opposite shows the pretty striped goby (Trimma cana), which grows to just 30 mm in length.

Gobies of the genus Eviota usually grow to between 25 and 30 mm in length and enjoy sitting on a coral, observing their surroundings. The photograph opposite shows Eviota bifasciata.  

The genus Elacatinus (formerly Gobiosoma) comprises numerous varieties which attain a maximum length of just 40 mm, making them suitable for a Nano Cube. The photograph shows Elacatinus multifasciatus.

The spikefin goby (Discordipinna griessingeri) is surely one of the most attractive gobies imaginable. It only attains a length of around 30 mm and is much too small for a normal-sized aquarium. In a Nano Cube it is in its element. Always keep this variety in pairs.

TIP: Keep fish in pairs!

While you should not keep more than two nano fish in a 30 l Nano Cube, the two fish you choose should ideally be a pair. These fish will not feel at home if they are forced to live on their own, without a partner.