Freshwater care
Choose and keep small schooling fish
Compare tetras, minnows and rainbowfish before mixing temperatures and water needs.
A school is a social need, not a decoration
Neon tetras, white cloud mountain minnows and many rainbowfish are all called schooling fish, yet they do not share one care sheet. Choose one species first and keep a proper group, commonly six or more, in a mature aquarium. A larger group often shows steadier behaviour and gives a more coherent display than collecting two of several kinds. Check the adult size and swimming room required by the exact species.
Match the water before the color
Neon tetras (Paracheirodon innesi) suit a stable, planted tropical aquarium with calm companions. White cloud mountain minnows (Tanichthys albonubes) generally appreciate cooler, well-oxygenated water and should not be placed automatically in a warm betta tank. Rainbowfish vary greatly: small species may fit a medium community, while larger Melanotaenia need a long tank with open swimming space. FishBase or a specialist source can confirm the particular species rather than the broad shop label.
Acclimate and observe
Buy active fish with normal body shape and no visible spots or damaged fins. A mature, cycled tank is especially important for small fish, which can respond quickly to a water-quality swing. Acclimate them to the aquarium water according to a sound method, avoid pouring shop water into the display if possible, and watch whether every fish feeds after introduction. Provide plants around the edges and some open water. Keep a lid for active jumpers.
Choose peaceful tank mates that cannot swallow the school. Do not interpret hiding on the first day as proof of disease; compare it with breathing, appetite, water tests and behaviour over the next days. When one fish separates from the group and declines, check water quality and seek expert advice before medicating the whole tank.
Source and further reading
Check the scientific name and local laws for any species you plan to buy, keep, catch or release. Care needs vary by species and circumstances.