What can I keep in this small tank?
I have an old, 21 l fish tank that could support either temperate or tropical fish. Please could you give me some recommendations on livestock? I was thinking of maybe keeping some Corydoras pygmaeus. Any other tips on plants and substrate would also be helpful.
TRISTAN SHAW, VIA EMAIL
BOB SAYS:I wouldn’t recommend keeping fish in aquariums with a volume of less than 25 l. Even tiny species like Corydoras pygmaeus need sufficient space to swim around and express their natural behaviours. As they are a shoaling species, often quite active in the mid-waters of the aquarium, then 21 l is too small for the required minimum group of six.
Instead, I would recommend you try your hand at shrimp, which are fascinating little inverts. Cherry shrimp, Neocaridina davidi, for example, are easy to keep and are now sold in orange, yellow, green, blue and black, as well as the bright red colour that gives them their common name. They are constantly active, picking their way around the tank, cleaning algae and detritus and should breed successfully.
A soft, sand substrate and a selection of easy to grow, smaller plant species like Anubias nana and Cryptocoryne such as C. beckettii 'Petchii' or some of the smaller C. wendtii varieties would be a good start plant wise, making a good background to show off the shrimp to their best effect.