If you have a small apartment but still want to keep fish, or if your child wants to have a few in his/her bedroom, a so-called ‘nano aquarium’ might seem like the right solution.
These smaller aquariums are increasingly available online and in pet shops. However, they are completely unsuitable for many marine animals in the long term, according to the German Association for Professional Nature, Animal and Species Protection (BNA).
Nano aquariums often have a rim length of 30 to 50 centimeters and a volume of much less than 54 liters. Ornamental fish, however, should be kept permanently in a tank with a volume of at least 54 liters, preferably more, according to the BNA. This corresponds approximately to an aquarium of 60 by 30 centimeters.
But are nano aquariums still useful? Yes, nano aquariums can be suitable for keeping small invertebrates, such as freshwater and saltwater shrimp, or even just aquatic plants, say the conservation experts. For example, the association recommends cherry shrimp (Neocaridina davidi).
If you want to keep ornamental fish in a slightly larger aquarium, you should keep an eye on their number. A maximum of two to three species per aquarium is usually the ideal number for the well-being of the animals – and the characters of the respective fish species should work well together.
Fish in larger, smaller aquariums should also be fed sparingly: enough so that they do not starve, but not so much that too many nutrients end up in the water and the water values become unbalanced.
The BNA recommends changing about 30 to 50% of the water every week and removing some sludge and dead plant remains. In addition, you should check the filter regularly and clean it if necessary.
