3.  What is their natural habitat like? 

Green neon tetras’ natural habitat is exclusively black waters, thick with vegetation, fallen branches, and organic matter. They prefer gentle water flow.

 The water they live in is acidic to very acidic. 

Picture above: South American Amazon waterway. A habitat a Green Neon Tetra would like.

6. What is the ideal aquarium setup for Green Neon Tetras?

Green Neon Tetras share some characteristics and tank preferences with other tetras. 

Aquarium size

Because of how small they are, GNT (Green Neon Tetras) can thrive in smaller aquariums. Best suggestion is to have one gallon of water to each tetra. If it were my tank, I would have 2 gallons of water for each fish.

Below is a video of 600 tetras in one round aquarium. This is really cool. Tap the picture to view the video. Opens in a new tab.

How to create GNT paradise in your home

Green neon tetras’ natural habitat consists of plants, fallen trees, roots, and rocks.

The water is what is called “black water” by seasoned fish keepers. This means it is filled with rotting plants and leaves which causes the water to become dark and acidic.

The soil in the GNT’s home is dark reddish-brown to black. These tells you what color the aquarium gravel should be. 

Picture above: Orinoco River (visible at the top of the photo) and an off shoot stream or pond. Perfect Green Neon Tetra environment.

Behavior and tank-mates

This peaceful fish species will need community tank mates that are also small and peaceful as well. This includes, but is not limited to, other tetras, mollies, and guppies. 

7.  What should green neon tetras be fed?

Diet in its natural habitat

GNT are omnivores.

Green Neon Tetras eat any small insect or zooplankton that they can fit in their mouths.

They also nibble on plant materials like algae, fallen fruit, and even leaves.

Feeding and dietary requirements

Green neon tetras are rather easy to feed. 

Give them just about any fish foods and they will chow down. This includes flake foods, frozen foods and cooked vegetables. 

Like all fish, GNT’s will eat until they die. Take care not to over feed them. 

How do you breed green neon tetras?

Mating, reproduction, and breeding

Green neon tetras are a polygynandrous species, meaning that males and females engage with multiple partners indiscriminately.

Subsequently, mating is commonplace, yet that does not make breeding an easy task. Green neon tetras require specific conditions to start the mating process (low pH of 6.5 or lower, very low water hardness plus plants and rocks. The survival rate for eggs and fry is low because of their high fragility and small size.

I’ve had cardinal tetras mate daily in the morning in a community 55 gallon tank I used to have. I used strictly reverse osmosis water which means 6.5 to maybe 7 pH and no hardness. I.E. super soft water with the temp. set at 78 degrees F.

How to tell males from females

The females might be a little rounder.

Breeding and hatching

If kept in a school, males will often compete for female attention and display brighter colors as they swim around her. If the female accepts, the breeding process starts.

Female green neon tetras lay over a hundred eggs on top of the substrate or plants with fine leaves, but always in shaded areas of the tank. Light and UV radiation will damage eggs and newborn green neon tetras, which is why lower illumination levels are required.

After the male fertilizes the eggs, they hatch within 24 hours. Green neon tetra fry are still sensitive to UV radiation, so they should be raised in a shaded / darker tank.

The fry can be fed infusoria or liquid fry food until they are large enough to take highly powdered flake food and baby brine shrimp.

8.  What are common diseases of Green Neon Tetras?

Green Neon Tetras are delicate fish that are not a common breed in the hobby. (I have seen them for sale in the local big box pet store in the past). Subsequently, odds are your fish were captured in the wild. This makes them more vulnerable to stress and common tank diseases.

It’s important for the well-being of your GNT’s that you understand the symptoms and treatment of prevalent diseases, such as the following.

Shock

It has been discussed how GNT’s are susceptible to fluctuating water conditions. Deteriorating water quality most always results in shock, stress, and vulnerability to further diseases is to keep your water parameters steady and avoid fluctuations. Likewise, make sure to add them to established and mature aquariums.

Ich

With shock comes Ich. Unstable water parameters and fluctuating temperature can induce the growth of protozoans responsible for this parasitic disease. I.E. This is the fish keeper’s fault.

Ich’s most distinctive symptom are white spots all across the fish’ body, clamped fins, appetite loss, and constant gasping.

Treating ich requires both medication and a shift in the tank’s water parameters. Malachite green, aquarium salt, and copper sulfate are sufficient to kill the parasite. Also increase the water temperature, as well as make larger, more frequent water changes. All of these steps show lead to complete recovery.

Neon Tetra Disease

The most significant threat to the health of your green neon tetra fish is the aptly named “neon tetra disease”, a prevalent disease for this species that has no known cure.

Of note:  I have read some fish keepers articles that have said the protozoan responsible for this disease is always present in all aquariums. 

Neon Tetra Disease is caused by Pleistophora hyphessobryconis, a protozoan that is often transmitted through infected live food, as well as through diseased fish being added to the tank. The infected fish develop damaging cysts, a dull coloring, and a curving of the spine. 

Once infected, the only solution is to remove the affected fish to avoid a widespread epidemic in the tank.

Conclusion

My opinion on keeping Neon Tetras or Green Neon Tetras in “don’t.” I’m fairly certain they will die quickly in your care.

That said, if you are really serious about making sure their water pH hangs around 6 and hardness is zero or nearly zero, you might have some luck at keeping GNT’s.

Leave a comment at the bottom of the page to let me know about your experience with Neon Tetra, GNT.s or Cardinal Tetras.