Tetras are South American fish that like to be in schools. Most are small, hardy and easy to keep. Some such as Neons and Cardinals are a little bit more sensitive to water quality. Except for the Pacu, that are vegetarian oriented omnivores, most Tetras are carnivores and will not eat algae or plant based foods, except when forced to in a commercial mix. Tetras benefit from raw or live meat in their diet. They tend to prefer soft acid waters in the mid to upper 6 pH range. They will do OK up to around 7.5. Water temps between 68 and 82 are fine.