Do fish need light in their aquarium?

I have a fish tank in which there are approximately 10 fish.

There is a light on the top of the tank, which I keep on during evening time. I Do not know during what time of the day I should keep it on.

1 Answer 1


It's important to turn the lights OFF at night, so fishes can sleep. During the day, light could be open for 6, 8 or 10 hours. Lights are important for you to look at your beautiful aquarium, but the fishes themselves are not in danger without light. Most of them will feel more safe hidden in the dark. Plants however are in danger without light.

You should search the light preferences and requirements of the exact species of fish that you have, because different fishes, different lights. You should google: "[fish type] light requirement" For example betta light requirements, corydoras light requirements... Some fishes might need shadow and feel nervous in too much light. I cannot give you an exact answer without knowing which fish you have. Overall most animals need a certain day/night cycle.

  • Since you mentioned plants in your answer, it's worth mentioning that plants might also require a certain type of light in order to thrive. @OP don't forget about the heat coming from the light - some types of lights can cook an aquarium if left on too long!
    – A C
    Dec 26, 2019 at 2:20

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