Pygmy cories are one of the only Corydoras species that can be kept in smaller aquariums. A minimum of 10 gallons (38l) is usually recommended. Like all Corydoras species, pygmy Cories should always be kept in larger groups (at least 8). When the shoal is not big enough, the fish will often become skittish and stressed. Providing plenty of hiding places in the form of aquarium plants and shrimp flats can help make them feel more at ease.
It’s very important to use a sandy substrate in the aquarium instead of gravel. If Cories are kept on gravel for too long their barbels will wear down, leaving them unable to properly search for food or behave naturally. In bad cases this can even lead to rot, which is very dangerous that close to the face of the fish! Cories that are kept on sand are also just much more fun to watch: I often see my pygmy Cories burying their faces up to their eyes into the sand when they’re foraging.