Do Fish Prefer Light Or Dark?

The answer to this question is not as simple as it may seem. While some fish do prefer light, others prefer dark.

It really depends on the species of fish. For example, some fish that live in deep water prefer dark because it is easier for them to hide from predators.

Other fish, like those that live in shallow water, prefer light because it helps them see better and find food.

Do fish need it dark at night?

Fish need darkness at night to rest and avoid predators. During the day, they are active and use their eyes to see.

When it is dark, they can rest and avoid being seen by predators.

Do fish like light at night?

There is some anecdotal evidence to suggest that fish may find light at night more stressful than light during the day. One study found that exposing guppies to light at night caused them to exhibit more stress-related behaviors, such as swimming in circles and being more aggressive.

  How Do I Know If My Betta Is Happy?

Additionally, some fish species are known to be nocturnal, which may account for their preference for darker environments. However, there is no definitive proof that fish dislike light at night and the results of any given study may not be representative of all fish species.

Do tropical fish need light at night?

It depends on the fish and its environment. Generally speaking, most tropical fish do not require light at night, as they are adapted to living in darkness.

However, some fish, such as corydoras catfish and some guppies, do prefer to have a little light at night to help them see and avoid predators. Some fish, such as tetras and plecos, can actually live without any light at all and will do just fine.

Do fish sleep?

Fish sleep in a similar way to humans. Fish eyes are positioned near the top of their head, allowing them to keep an eye on the water for predators or prey.

Some fish species sleep for a few hours at a time, while others may sleep for days at a time.

Do fish need blue light at night?

Fish do not require blue light at night to function, but some fish tanks use blue LED lighting to produce a calming effect.

Can fish see in the dark?

Fish see in the dark quite well, in fact they are well known for hunting in the dark. Some fish have special light-sensitive cells in their eyes that allow them to see in the dark.

Some fish, such as catfish, can see in the complete dark.

  How Do You Treat Fungus On A Betta Fish?

Do fish need complete darkness to sleep?

Fish do not need complete darkness to sleep. However, they do require some darkness so that their eyes can adjust to the darkness and so that they can sense movement and noise.

A common tank housing fish often has a light fixture near the bottom that provides some artificial light during the night, and this is often sufficient for fish to sleep.

What does blue light in fish tank do?

Blue light is a type of light that is shorter than red and green light. Blue light is used to stimulate the fish’s sight.

Some fish tanks use blue light to keep the fish healthy.

Why are my fish more active when the light is off?

There are a few potential reasons why your fish may be more active when the light is off. One possibility is that they are using the dark environment as a cue to forage for food.

Another possibility is that the dark environment encourages them to hide from predators.

Is it OK for my fish to be in the dark?

Fish are sensitive to changes in light, so it is best to keep them in the dark as much as possible. This will help to keep them healthy and happy.

Can fish sleep with light on?

Fish can sleep with light on, but they may not be able to get a good night’s sleep. Many fish species are adapted to a 24-hour light-dark cycle, so turning on lights during the day can disrupt their sleep.

  What Does It Look Like When A Fish Has Ick?

Additionally, artificial light can cause fish to produce excess stress hormones, which can lead to health problems.

Do aquarium fish prefer light or dark?

Light is necessary for photosynthesis in aquatic plants. As a result, light encourages the growth of plants in an aquarium.

Conversely, dark environments encourage the growth of algae. Algae forms the bulk of the diet for many aquarium fish.

Aquarium fish typically prefer light over dark. However, some fish, such as cichlids, can adapt to a darker environment.


A study was conducted to find out if fish prefer light or dark. The study found that the fish preferred the light.