Do neon tetras need light at night?

No, neon tetras do not need light at night. Neon tetras require 8–10 hours of darkness and 12–14 hours of light during the day every day to maintain a healthy circadian rhythm.

Consider using an aquarium light timer to help you make sure your neon tetras are well looked after and getting adequate amounts of light and darkness, even if you are out during the day.