Otocinclus: Oto Catfish Care Guide ...
Otocinclus: Oto Catfish Care Guide & Species Profile

Are five neon tetras enough?

No, five neon tetras are not enough. You should keep a minimum of six neon tetras in your tank because they are schooling fish that get stressed and die if there are not enough of them. The ideal amount of neon tetras you should keep is 10.

The more neon tetras you keep, the better, but make sure you have the right amount of water in your tank to accommodate the number of tetras. If you have more than 15 neon tetras, make sure you have at least 20 gallons (76 litres) of water in your aquarium. Do not overcrowd your fish tank.