Can Goldfish See In The Dark? {Do They Have Night Vision}

Have you ever wondered after turning off all the lights at night, can goldfish see in the dark?

If they are not sleeping can they move around the tank ok? What if they are hungry, can they eat?

I will cover all this and more below.

Can Goldfish See In The Dark

Goldfish cannot see very well in the dark, but they have a highly developed sense of smell which they will use to navigate around the tank at night if they need to. They will also use vibrations in the water to help them sense where they are going.

Goldfish also have good color vision and can distinguish between different colors, although their ability to see in the dark is not as developed as their diurnal (daytime) vision.

In low-light conditions, their eyes adjust to allow more light to enter and be detected by specialized cells called rods, which are responsible for vision in dim light.

While goldfish can navigate and forage in low-light environments, it’s important to provide them with appropriate lighting conditions and avoid keeping them in complete darkness for extended periods.

Adequate lighting not only benefits their vision but also helps regulate their biological rhythms and overall well-being.

Can Goldfish See In The Dark

Should I Turn Off The Light In My Goldfish Tank At Night?

The fish do not need light and it is best to make sure the lights are turned off at night. If you leave the lights on, the fish will not be able to sleep and this will lead the fish to become stressed.

If your fish are unable to get enough sleep the stress level in the fish will continue to raise and can even lead to death of the fish.

How much sleep does a goldfish need? A goldfish requires a minimum of 6 hours sleep a night.  The recommended amount of sleep a goldfish should have is 8 – 12 hours a day.

If possible keep the fish in a well lit environment for 12 hours and in dark for 12 hours.

For more information about goldfish sleeping take a look at this article I wrote.

YouTube video

Do Goldfish Need a Light at Night

Goldfish do not require a light at night. In fact, it is recommended to provide them with a period of darkness during the night. Just like most animals, goldfish have a natural circadian rhythm that includes periods of rest and activity.

Providing a dark environment at night allows them to rest and maintain a healthy sleep cycle.

Excessive or constant exposure to light can disrupt their natural biological rhythms and stress the fish.

It’s important to establish a regular light cycle for your goldfish, typically around 12 hours of light and 12 hours of darkness. This can be achieved by using a timer to control the aquarium lighting.

Can I Leave My Aquarium Light On 24 / 7?

You should not leave the aquarium light on for more than 12 hours a day.  Fish require around 8 – 12 hours a sleep a day and the darkness will help them to settle and fall asleep.

Fish generally cannot fall asleep when the aquarium light is on.  If your fish cannot sleep it will become stressed and this can even lead to the fish dying.

Do Goldfish Like Darkness

Goldfish are not necessarily “preference-driven” animals like humans, so it’s difficult to say whether they like darkness in the same way we might. However, goldfish, like many other fish, have evolved to have a natural circadian rhythm.

This means they have a biological need for periods of darkness and rest.

Providing a dark environment at night allows goldfish to rest and maintain a healthy sleep cycle.

Just like any other living creature, they require time to rest, recuperate, and recharge. Constant exposure to light can disrupt their natural biological rhythms and cause stress.

While goldfish may not actively seek out darkness as a preference, providing them with a regular light cycle of around 12 hours of light and 12 hours of darkness is generally considered best for their overall well-being and health.

Do Goldfish Need Darkness to Sleep

Goldfish do not necessarily require complete darkness to sleep, but they do need a period of reduced light or darkness to rest and maintain a healthy sleep cycle.

While goldfish do not have eyelids, they can still enter a state of rest where their activity levels decrease, and they may find a quiet spot to settle down.

Goldfish are diurnal animals, meaning they are active during the day and rest during the night. Providing a dark environment or dimming the lights during the night helps create a more suitable sleeping environment for them.

This darkness helps them relax and minimizes potential disturbances that could disrupt their sleep patterns.

Can Goldfish Navigate The Fish Tank In The Dark

Goldfish use their amazing sense of smell to easily navigate around the fish tank at night, They also sense vibrations in the water to help them navigate where to go.

Goldfish require at least 12 hours of light a day, It is important they get light every day because this helps with their natural cycle.

Do Goldfish Require Complete Darkness To Sleep? Fish require darkness to sleep, it is important for your goldfish as they require 8 – 12 hours sleep every day.

Can Goldfish Eat In The Dark?

Goldfish have an amazing sense of smell which means they will have no trouble to locate a meal when it is dark and they can not see clearly.

Having said that goldfish usually eat during the day and not through out the night.  They will only eat in the dark if they are very hungry or not getting enough light during the day.

Will a Goldfish Lose Its Color if You Keep It in a Dark Room

No, Keeping a goldfish in a dark room alone is unlikely to cause a significant loss of color. The coloration of a goldfish is primarily determined by its genetic makeup and can be influenced by factors such as age, diet, water quality, and overall health.

However, it’s important to note that light exposure can play a role in enhancing or fading the coloration of some goldfish varieties.

Certain goldfish, such as those with metallic or iridescent scales, may exhibit more vibrant colors when exposed to proper lighting conditions.

Inadequate lighting or extended periods of darkness could potentially affect their color display, as they may not receive the optimal light necessary to showcase their full color potential.

Why Do My Goldfish Go Crazy When I Turn The Lights On?

The most likely cause is that they were sleeping when it was dark and you startled them and made them disorientated for a few seconds.

If they were awake you probably just scared them.

I recommend you place your aquarium somewhere it will get natural light, this way the light will increase slowly in the morning and is less likely to upset the fish.

Do Goldfish Have Good Eye Sight?

Goldfish have amazing eye site
and can even see objects up to 15 feet away.  In fact a goldfish eyesight is superior to us humans.

Do Goldfish Have Good Eye Sight

This is why you might see your goldfish dart around in the water if they see something in the room move, even when the other side of the room.

They also only see three colours red, green and blue like us, and they can see ultraviolet light which makes them sensitive to polarized light.



Hello, I'm Jason. I'm the guy behind I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.