Active, colorful, enchanting, and simple to care for, it’s no wonder neon tetras are so popular.
But, if you want to get the most enjoyment out of your buddies, you’ll want to provide the right care.
Luckily, it’s not so hard. And in this guide, I’ll walk you through how you can provide the optimal care.
Neon tetras (Paracheirodon innesi) are a small schooling fish found in tropical freshwater rivers and streams in South America.
Neons have been a mainstay of the aquarium trade for decades. They’re pretty much available year round at any live fish store.
Neons are fairly easy to breed in captivity, so most of the ones found in the aquarium trade have been farm raised.
This is a good thing. It means that over the generations they’ve adapted to living in aquarium conditions. This makes them less finicky about water conditions than wild caught species.
What do Neon Tetras Look Like?
True or “wild form” neon tetras have a light blue head and back.
They have a distinctive bright blue, iridescent stripe on both sides of their body that runs from their nose to their adipose fin.
They have a red stripe on both sides that runs from their anal fin to their tail, and their abdomens are a shiny silver color.
A neon’s fins are nearly transparent, the color really doesn’t bleed over to them.
Varieties of Neon Tetra
Long fin neons look like…well…exactly like the name sounds. They have fins nearly double the length of wild form. They kind of remind me of tiny little bettas.
Albino neon tetras lack all red and blue color. They have a pearly white, shimmery color.
Like most albinos, they have pink eyes.
Their heads and backs are missing the light blue color. Some still have the bright blue stripe and nearly all have the red stripe on the tail.
Their eyes are a striking blue color.
Instead of having the bright iridescent stripe down the sides of the body, they have only a bright blue diamond shape on their heads.
Green Neon Tetras
These guys aren’t actually neon tetras at all. They’re a different species, Paracheirodon simulans.
They look really similar and so they got lumped in with true neon tetras.
Greens have a smaller red stripe along their tails. Instead of a blue head and back, it’s more of a green color. Their neon stripe is also more of a green blue.
How Long Do Neon Tetras Live?
Believe it or not, these little guys have a really long lifespan. You can expect them to live as long as 8 years in an aquarium.
How Big Do Neon Tetras Get?
Neon tetras aren’t big fish at all. They only grow to about 1.2 inches (3 centimeters).
Cardinal Tetra vs Neon Tetra
Cardinal tetras and neon tetras look very similar but are actually two different species.
Cardinal tetras (Paracheirodon axelrodi) also have red and blue stripes, including a bright neon blue one.
But the red and blue stripes run the entire length of the body instead of ending halfway along the body like neons.
Cardinals also get a bit bigger, growing up to 2 inches long (5 centimeters).
Setting Up a Neon Tetra Tank
Let’s go through the process of how you can set up your own Neon Tetra aquarium.
How Many Neons Should You Get?
Keeping neons in too small a group can make them stressed and unhappy.
Just imagine, you’ve got a big group of friends and you’re used to hanging out with all your buddies. But then someone scoops you up with a huge net and puts you in solitary confinement for the rest of your life.
You wouldn’t be too happy about this, and you’d probably be pretty stressed out, too.
Neons should be kept in a group of at least six. Any less than this and they might start getting nervous and aggressive with each other. Keep in mind, this is an absolute minimum.
The more the merrier with these little guys. Schooling fish feel more secure when they can gang together with a lot of the same species and rely on safety in numbers.
They will also school more tightly with a big group, which is really awesome to see in the tank.
And do not get just two. If one of the neons starts to get aggressive, it only has one other fish to pick on.
Just picture a schoolyard bully with only one kid to push around. The poor thing will just get pounded to death.
With a larger group, that aggression gets spread out so no one fish is singled out and harassed all the time.
Best Tank Size for Neon Tetras
Since neons don’t get very big, a single fish does not need a huge amount of space, just a gallon or two.
But, keep in mind that you’ve got to get a group of them. For this reason, I really don’t recommend putting them in anything smaller than a 10 gallon for a group of six.
There’s another consideration as well. Neons look their best in a bigger tank. More room lets them school together and swim up and down the tank.
Believe me, a large school swimming in a larger tank is so much prettier than a small group huddled in a tiny tank.
Since they’re mid-water fish, a taller aquarium gives them more room to move around and feel comfortable.
The Nitrogen Cycle
Fish and invertebrates in the aquarium put off waste, urine and feces.
These wastes sink to the bottom of the tank and start to break down. This is really bad because it creates ammonia (NH3 ), which is pretty darn toxic. Left unchecked, it would keep building up until it killed everything in the aquarium.
Ammonia can actually chemically burn a fish’s gills, causing permanent damage or death.
Yep, that’s just as horrible as it sounds.
Lucky for us, beneficial bacteria colonize the filters and substrate in our tanks.
There are several different kinds of beneficial bacteria. One kind turns ammonia into nitrite (NO2 -1). Nitrite is just as toxic as ammonia. Another kind of beneficial bacteria turns the nitrite into nitrate (NO3- ).
This whole process of ammonia being processed into nitrite and nitrate is known as the nitrogen cycle.
Nitrate is much less toxic than either ammonia or nitrite. It can be allowed to build up somewhat, just make sure that you perform weekly 25-50% water changes so it doesn’t get too out of hand. But here’s the thing.
The bacteria don’t move in and start processing ammonia for you in a day or two. It can take 6-8 weeks, if not more, for beneficial bacteria to start growing in your tank.
Getting these bacteria to colonize your filter so you can keep fish in the tank is called cycling the tank. During this process, any fish in the tank are vulnerable to ammonia and nitrite poisoning.
Pro Tip: Performing a fishless cycle is the best way to ensure your tank is fully cycled before you add fish. This saves you money on replacing fish and also is more humane.
It is absolutely critical that neons only be added to a tank that is well cycled.
They do not tolerate ammonia or nitrite well at all. They need nearly pristine water with no ammonia, no nitrite and low nitrates.
Water Parameters for Neon Tetras
Since neons originate from the Amazon river basin, it’s best to mimic these conditions as much as possible.
This means soft, slightly acidic water is best for them.
Temperature: 72°-76°F (22.2°-24.4°C)
Ammonia: 0 ppm
Nitrite: 0 ppm
Nitrate: <20 ppm
GH: <10 dGH (<166.7 ppm)
KH: 1-2 dKH (17.8- 35.8ppm)
Substrate for Neons
Neons don’t really have a specific need for a certain kind of substrate. They’re mid-water swimmers and don’t really hang out at the bottom of the tank very much.
But, you should avoid using aragonite sand as your substrate.
It’s made of calcium carbonate (CaCO3). Aragonite will leach calcium and carbonate into your water, raising the GH, KH and pH.
What Kind of Filtration do Neon Tetras Need?
Neons don’t necessarily have specific filtration needs.
The biggest thing to remember is to get a filter that is rated for the volume of your tank. That way, you should have enough capacity for the beneficial bacteria that process ammonia.
Look for the GPH rating (gallons per hour), and make sure it’s 4x higher than your tank size and you’ll be good.
E.g. GPH 40 for 10 gallon.
Lighting for Neon Tetras
Neons come mostly from blackwater environments. Millions of leaves fall into the rivers and streams where they breaks down. The leaves put off tannic acid (tannins) that dye the water a dark brown.
Since they evolved to live in this dark brown water, neons really aren’t big fans of bright light.
Kind of like me with spiders.
But seriously, these fish would actually be happier with dim lights instead of bright ones.
If you’re going to keep live plants in your tetra tank, it’s better to go with species that can grow in low or medium light.
Or you can include floating plants that will diffuse the light that hits the water and give the neons shady areas to retreat to.
Fry tanks are a bit different. If you’re raising eggs and fry, don’t light the tank at all.
Neon tetra eggs and fry are very sensitive to light. The light will actually kill them, so it’s best to keep the tank as dark as possible until the fry are several weeks old.
Heating a Neon Tank
Neons are most definitely tropical fish. You will absolutely need to add a heater to the tank so that you keep it at a steady 72°-76°F (22.2°-24.4°C).
For breeding, it’s better to keep the tanks at 75°-76°F (23.9°-24.4°C).
Plants and Decor for Neon Terta Aquariums
It’s best to provide your neons with a mixed environment with some open swimming space and lots of plant cover.
They’ll school together in open areas when they feel secure and dart into plants when they feel threatened.
They love tall plants like Ludwigia repens, Brazilian pennywort (also works as a floating plant), vallisneria, cabomba or Cryptocoryne wendtii.
Neons also like floating plants like frogbit, dwarf water lettuce or red river floaters. They’ll swim around in the roots that hang down into the water column.
As an added bonus, live plants help to remove nitrates from your water. So they’re functional and beautiful. It’s always nice when those come together.
If you’re just not into live plants, tall fake plants are an option.
As for other kinds of decor, that’s really just a matter of taste with these guys. They don’t use things like caves or stake out a territory.
So if you want the cool castle that has bubbles and hidey caves, go ahead! Just don’t expect the neons to set up shop in it.
Feeding Neon Tetras
Neons are omnivores, meaning they eat both plants and animals in the wild.
What are the Best Foods for Neons?
It’s best to mimic this diet in the aquarium:
- Balanced, high quality flake food.
- Sinking micro-pellets.
As a treat:
- Freeze dried or frozen bloodworms.
- Frozen brine shrimp.
Pro Tip: You can raise your own brine shrimp for cheap and always have live foods to supplement their diet.
How Often Should You Feed Neons?
It’s fine to feed neon tetras every day. They are an active fish and so have high energy requirements.
You may even consider dividing their meals so that you feed them in the morning and again in the evening.
Behavior & Tank Mates
Neons are small, peaceful fish. So they do best with other fish that have a similar personality.
Large, aggressive fish will bully and possibly eat them.
Good tank mates for neon tetras:
– Other tetra species like black skirt tetras, black neons or cardinal tetras
– Livebearers like platies, endlers or guppies
– Corydoras catfish
– Otoclinus catfish
– Clown or bristlenose plecos
– Boesemani rainbow fish (these get over 6 inches but are very non-aggressive)
– Freshwater shrimp like red cherry, ghost or red/black crystal
Fish to avoid:
– Anything listed as aggressive or semi-aggressive
Breeding Neon Tetras
Let’s go through the process for breeding neon tetras:
Set Up Food for Fry
You should set up an infusoria culture at least a week before you start breeding your fish so you have food for your newly hatched fry.
It’s also recommended to feed fry either baby brine shrimp or Hikari First Bites for a few weeks. For the brine shrimp, you’d need to set up a hatchery once your fry are about a week old.
Conditioning the Parents
In order to get neons ready to spawn, you’re best bet is to start feeding them protein rich foods.
The high protein will trigger females to start producing eggs, which actually makes them easier to sex.
Foods like brine shrimp and frozen bloodworms should be offered for 2 weeks.
How to Sex Neon Tetras
The belly of a female neon tetra will look more rounded than a male’s. This is because she is carrying eggs in her abdomen.
Also, the blue stripe on a female’s body will have a curve to it because of her rounded abdomen, compared to the very straight blue line on a male.
How to Set Up a Breeding Tank
It’s essential to set up a separate breeding tank. Otherwise, the eggs and fry will just get eaten by adults in the main tank.
Neons are egg scatterers. Basically, the female releases batches of eggs and the male swoops in and quickly fertilizes them before they sink to the substrate.
- 5-10 gallon tank with a lid
- Heater Seasoned sponge filter and powerhead or air pump ( run the sponge filter in your main tank for several weeks so that beneficial bacteria can colonize it)
- Peat – make sure that it has no added pesticides or fertilizers. Peat labeled 100% organic or marketed for aquarium use is best. You need enough to cover the bottom of the tank with a 1 inch layer Java moss or spawning matt – this helps keep hungry parents from eating eggs
- Aquarium thermometer
- You do not need lights
Steps for Breeding
- Soak the peat in warm water to rehydrate it.
- Spread a 1 inch layer in the bottom of the tank and spread java moss or breeding mat over the peat.
- Fill the tank with water and install the heater. The peat will make the water VERY dark at first. This is totally normal. The color will settle down after a few hours and the tank will look like it’s full of brewed tea.
- Let the tank get up to temp for several hours. The temperature should be between 75°-76°F (23.9°-24.4°C).
- Place the sponge filter in the tank and get it up and running.
- Add neons to the tank. Some people just put a pair of adults in, some swear by a group.
- Let the adults hang out in the breeding tank for a day or two. The peat will drop the pH and help trigger the fish to spawn. Keep feeding them protein rich foods.
- Do a 50% water change on the tank. Don’t stir up the bottom. Just siphon water from the water column. This simulates the rainy season in the Amazon and helps trigger fish to spawn.
The Breeding Process (What Happens?)
Females will start to drop eggs into the water and the male will dash in and fertilize them.
The eggs are tiny and just about impossible to see once they’re on the bottom.
Give the adults about 5 days in the tank after your 50% water change. Then remove them.
Do not let bright light and/or sunlight hit the tank. Strong light can kill the eggs and fry. If you need to check on the tank, use a flashlight to quickly take a look.
How to Raise Neon Tetra Fry
Keep the tank dark for at least two weeks.
Eggs will hatch in about 36 hours. 5 days after hatching, the fry become free swimming.
At this point, use a turkey baster to add infusoria to the tank twice a day for about 5 days.
The fry can then be fed freshly hatched brine shrimp or a prepared fry food like Hikari First Bites for the next several weeks.
Once the fry are about a month old, they can then be fed just like adults.
Neon Tetra Disease and Treatment
Now we’ll run through neon tetra disease, what causes it, and how you can treat/prevent it.
Please note, I am not a vet, this should be used as a general awareness guide. If you are concerned about your neons, consult a professional.
We will not answer any comments about illness.
What Causes Neon Tetra Disease?
Neon tetra disease is caused by a protozoan organism, Pleistophora hyphessobryconis.
Neons get infected by eating contaminated food, like live tubifex worms, that carries the protozoan’s spores. Or from feeding on an infected dead fish.
Symptoms of Neon Tetra Disease
- Fish stop schooling with others and hide
- Lack of coordination
- White patches on body
- Lumps under the skin
- Spinal deformities
Treating Neon Tetra Disease
I’ll be honest with you. There really isn’t a recommended treatment for this disease.
If you think one or more of your fish has neon tetra disease, they should be moved to a hospital tank immediately to help stop the infection from spreading.
There are some bacterial infections that have really similar symptoms. You can try treating the tank with kanamycin.
But if the kanamycin doesn’t improve things, then the fish do have true neon tetra disease.
Diseased fish will need to be euthanized.
I know, it’s really sad. But it’s better to humanely euthanize the fish than have them suffer from what is already a fatal infection.
Are Neon Tetras Right for Your Aquarium?
There’s a reason that these little fish are so popular in the aquarium hobby.
They’re beautiful and are just happy go lucky little critters. They really are a great addition to any peaceful community tank.
Make sure to keep them in a group, the bigger the better.
Although they’re too sensitive for a cycling tank, in an established aquarium you can enjoy them for many years.
Neons breed readily but you’ll need to do some preparation if you want to raise fry to adulthood.
I really think this is a gorgeous species that can be so striking when kept under the right conditions. I highly recommend them.