Do Color Changing Lights Bother Fish, Cause Stress?

Last Updated on March 22, 2022 by cmoarz

We’ve all seen those cool colorful LED lights that you can buy to put in your fish tank.

They are quite popular these days and go right along with the ‘LED in everything’ fad.

But have you ever wondered if those bright, changing, or flashing lights bother fish? Do they cause stress?

There are several things fish don’t like, Flashing lights that mimic storms, Strong lights which are too bright, lights that change color too frequently, or colors that aren’t natural such as a deep blue at night and a white or soft yellow during the day.

To answer the question do color-changing lights bother fish, the answer is yes. Flashing lights simulate storms which stress the fish out and they will hide.

Unnatural colors can also stress the fish out. Very rare in nature are there bright pink or red lights, and lights that change color frequently simply don’t exist in a natural setting.

That’s not to say fish can’t get used to 1 solid color that’s outside of nature, provided it’s not too intense.

A dull orange for example could be considered a more or less safe color light to provide your fish during the day.

The most important thing is consistency. Pick a color and stick to it. Make sure it’s not too bright and unnatural looking and your fish should be fine with it. Avoid automatic color-changing strips.

Of course, Our recommendation is always going to be a soft yellow/white light during the day and a low dull blue light at night (if you want to light your tank at night) to mimic moonlight in deep water.

At the end of the day, ask yourself if you would like to sit all day under a pink or blue, etc light in your house. It’s fun at first but quickly becomes a major strain on the eyes.

Your fish are no different!

Do changing lights affect fish?

If you just swap a normal aquarium bulb with another normal aquarium bulb (or LEDs), there shouldn’t be any issues.

If you’re swapping out a normal aquarium bulb with a colored LED light (or another type of light that changes), it’s best to stick with one color. Fish can get used to different colors, but it’s best not to change them too frequently.

Stress responses can include rapid swimming, hiding under aquarium objects and decorations, and trying to escape from the surface and the light.

Avoiding lights that change color rapidly, or that are too bright, will help to reduce stress in your fish.

It’s important to note that not all fish respond the same way to light. Some fish are more sensitive than others, and some fish may not be bothered by color-changing lights at all.

If you’re unsure whether or not your fish will be stressed by colored LED lights, it’s best to err on the side of caution and avoid using them.

What color lights do fish like?

Fish like natural color lights, these colors can include dark blue (or purple) at night, white or yellow during the day.

Nocturnal fish might approve of red lights as well as it’s easier on their eyes.

Light intensity is a bigger factor than the color itself. Absurdly bright lights will stress fish out, no matter the color.

A good rule of thumb is to make sure the light intensity is not too different from what they would experience in their natural habitat. This will help reduce stress and keep them comfortable.

In general, it’s best to avoid using colored LED lights if possible and try to keep within natural colorations by simulating sun and darkness.

Do normal aquarium lights bother fish?

This depends on the intensity of the light and how close the fish is to it. If the light is too bright, it can bother the fish and cause stress.

It’s best to keep the light intensity at a level that is comfortable for you, and not so bright that it hurts your eyes. This will help reduce stress in your fish.

You should also avoid using lights that flicker or change color rapidly, as these can also cause stress in fish.

Stick to using natural light colors whenever possible, and adjust the light intensity to find what is comfortable for both you and your fish.


Owner of and also owner of actual Aquarium Gravel believe it or not! ;). Setting up beautiful aquarium sceneries and habitats since I was very young. Enjoy!