You might have heard some tetras glow in the dark. A few months back I came to know about glow tetras. I was wondering if neon tetras glow in the dark or not. It was very confusing at first. So, I started researching this topic “Do neon tetra fish glow in the dark?”.
Neon tetras don’t glow in the dark, but the shiny and saturated fluorescent blue color on their body reflects under the glow of black light that emits UV rays. This creates a light show on the aquarium, which is just the reflection of the black light.
In this article, I will discuss how you can make your neon tetras glow and why neon tetras glow under black light. So, without further ado, let’s get started!
Do Neon Tetras Glow Naturally?
Noen tetras don’t glow naturally, which you might have seen on the internet. However, their neon color consists of fluorescent color that reflects under black light. There is nothing that neon tetra is doing to naturally glow herself.
However, if you want to see the natural light show on your aquarium, you will just need a black light that emits UV rays, neon tetras on your aquarium will reflect the fluorescent color and will create a light show.
What Is Black Light?
A black light is a kind of light that mainly emits UV rays and a small amount of normal or visible light.
Blacklight is popular among aquarists who are into glow tetra fishes. Fluorescent colors glow under UV rays. Glow tetras are genetically modified to have fluorescent colors, and that’s why they glow under black light.
So, what about neon tetras? Neon tetras are not genetically modified to glow. So, how come they also glow under black light? Let’s talk about that.
However, neon tetras have bright and saturated blue color which
Why Do Neon Tetras Glow?
Neon tetras naturally have a bright blue color on their body which is fluorescent in nature. Having fluorescent color does not mean that neon tetras will generally glow.
We can not see black lights or UV rays with naked eyes. All the fluorescent colors can absorb UV lights, and they emit a certain wavelength of light which falls under the visible light wavelength spectrum.
When neon tetras are exposed under black light, the blue color in their body absorbs UV rays and reflects the blue color, and that’s why it feels like neon tetras are glowing under black light.
How Do You Make Tetras Glow?
If you just bought glo tetras and thought about how to make them glow? Well, follow the steps below and you will be able to make them glow in no time.
Step 1: Get Tetras with Fluorescent Colors
First, let’s make one thing clear. Not all types of tetras will glow. There are maybe around 20 species of tetras.
But only glo tetras, neon tetras, and cardinal tetras have bright colors which glow under black light.
I suggest you buy the glo tetras. They look mind-blowing when they glow.
Step 2: Replace Your Aquarium Light With Black Light:
Tetras don’t emit light naturally. If you just buy a tetra and keep it inside your aquarium, they just won’t glow by themselves.
So, install black light on your aquarium. Black lights contain UV rays. Don’t worry, these UV rays won’t harm your fish.
Step 3: Get Rid of The Surrounding Lights:
You can not see the tetras glow if there are a lot of lights in the room. This step is pretty simple. Get rid of all the surrounding lights in your room and make the room dark.
Step 4: Turn The Black Light On:
After making the whole room dark, turn on the blacklight. You will see that the tetras are glowing, and their color looks really amazing.
Check out the picture below:

How Do Glowlight Tetras Get Their Color?
Glow Light Tetras are genetically modified tetras by a company called GloFish. Glowlight tetras can not be found in nature; however, they are very popular among aquarists.
Glowlight tetras are genetically modified organisms. They got their color from fluorescent protein genes, which are natural genes found in marine organisms.
GloFish company genetically modified the black and white tetras to get this fluorescent protein gene which glows under black light.
Fluorescent colors naturally absorb the long-wave UV light and reflect the glowing color to the viewer. Any fish that is fluorescent will glow under blacklight or UV light.
Neon tetra Vs. Glowlight Tetra: What’s the difference?
The main difference between neon tetra and glowlight tetra is; neon tetras are natural fish that can be found in the wild and glowlight tetras are black tetras that are genetically modified to glow under UV light.
However, both neon tetra and glowlight tetra reflect bright colors under UV or Blacklight because both of these fishes have fluorescent colors that absorb UV light and then reflect the glowing color.
Glowlight tetras can be found in eight different colors from GloFish, whereas neon tetras have only one color. Black and white tetras were genetically modified to make them glowlight tetra.
Related Questions:
Do Neon Tetras Change Color at Night?
Neon tetras don’t change color at night. During the night, their color might look dull in comparison to daytime because of the amount of surrounding lights.
Under good conditions of light, neon tetras look very bright and beautiful. But when the light is dim, their colors don’t pop up much, for which many people have a misconception that they change their color at night, which is actually not true.
Are Neon Tetras Dyed?
Neon tetras are not dyed, but neon tetras consist of bright fluorescent color that reflects under UV or black light, making anyone think that neon tetras are dyed.
Final Thoughts:
There you go! Neon tetras don’t glow in the dark. But they look really amazing under black light.
If you install a black light above your neon tetra fish tank, you will see a unique light show as the shiny blue stripe on their body glows under black light.
Truth is, the light is actually reflected back on the viewer’s eyes from the body of the neon tetras which produce a glowing effect. Your neon tetras won’t emit light naturally from their body.
Are you disappointed to learn that your neon tetras won’t emit light in the dark? Also, I would love to know, what do you think about genetically modified glow tetras?
So, let me know your thoughts in the comments below. That’s all for today! Take care.