Tetras are popular fish to keep in a home aquarium, due to their bright colors and simple care requirements. Many species of tetras exist, but among the popular kinds are neon tetras and cardinal tetras. The care requirements of each species varies slightly, so it's important to research the specific needs of the kind that you keep.
Like other tropical fish, tetras require the lights to be on in their tanks for 12 to 14 hours each day. This will help them to maintain a proper circadian rhythm. It's best to put your lights on a timer so that your fish can settle into a routine. Since certain tetra species, such as neon tetra and glowlight tetra, prefer subdued lighting, a well-planted tank is ideal for them. However, you should check the exact lighting preferences of the tetra species you keep. In a freshwater tank, you can get away with using a low-watt fluorescent light, between 18 and 40 watts, but if you plan on keeping live plants, your fluorescent light will need to put out roughly 2 to 5 watts per gallon of water in your aquarium.