big neon tetra

Why Is My Neon Tetra Not Growing?

One of the most common questions that I get asked is why is my neon tetra not growing. Many people think that just because a fish is a neon tetra, it will automatically grow to be big or at least bigger than what it was when they bought it. But unfortunately, this is not true at all. There are many factors that determine how big your fish will grow and if these factors do not work well together then you might end up with smaller than normal-sized neon tetras! So what are these factors? What can cause your baby fish to stay small?

You Need To Understand A Few Things

The size of your fish will depend on a number of factors, including the quality of the water they are living in, their food, and their tank or other living space. Neon tetras are a schooling species and prefer to be kept in groups. When you have more than one neon tetra fish in your aquarium it is important to provide them with plenty of space and good water quality so that all the fish can grow up healthy.

Water quality plays an important role when keeping neon tetras because if there isn’t enough oxygen in the water for them to breathe then they will become stressed out which may cause them not to grow properly or even die eventually if left untreated long-term (depending on how serious it gets). If you notice any signs that could mean there’s not enough oxygen around such as discoloration due to lack thereof then this would be something worth checking into further before deciding whether or not something needs to be done about it right away; otherwise, just keep a note so that if anything does happen later down the road then hopefully we’ll know why by examining these past records closely.”

9 Common Reasons Why Your Neon Tetra Is Not Growing

As you know there can be many reasons why your neon tetra is not growing but I have compiled a list of 9 most common ones:

1- Overcrowding

neon tetras overcrowding

Overcrowding is a common reason why fish don’t grow. Neon tetras grow to about 2 inches long and live for 5 to 7 years in the wild, but they can live 10 times as long in captivity if they’re properly cared for.

To help your neon tetras grow, you’ll need to make sure that there’s plenty of space for them. Neon tetras are schooling fish, so they should always be kept in groups of at least five or six fish. Because these fish need more food than other aquarium inhabitants, their tank should also be larger: a 30-gallon tank is ideal for keeping one neon tetra; two or three neons would require a 55-gallon tank, and four or five neons will need an 80-gallon aquarium.

Because schooling fish tend to eat more than other types of aquarium inhabitants (and because all those extra mouths will increase the amount of waste your tank produces), it’s especially important that you keep the water clean with regular water changes and filter maintenance, while providing plenty of oxygen by using an air pump or aerating stone on top of the water surface (don’t put it below!).

2- Stress

Although it’s not common, stress can also be one of the causes of slow growth in your neon tetra. Stress is a major factor when it comes to fish because even if they are healthy, they can still be affected by stressors like water quality, diet, tank mates, and temperature.

There are many ways you can cause your fish to become stressed: for example by adding too many fish into an aquarium at once or having them compete with each other for food.

3- High Nitrate Level

neon tetra in a fish tank

If the nitrate levels in your aquarium are high enough to cause harm, it’s possible that your neon tetra isn’t growing because of this.

Nitrates byproducts of fish waste and uneaten food accumulate in water as time goes on. These nitrates can be toxic to fish if they reach high enough levels. Keeping an eye on these nitrate levels is one way for you to keep tabs on how well you’re doing with keeping your aquarium clean and healthy.

Some ways that you can lower your tank’s nitrate level include:

1- Water Changes: If there is too much waste building up in the tank, it’s a good idea to remove some water from the tank every few weeks and replace it with fresh saltwater or pond water (in an emergency). This will dilute the amount of toxins in the water, which will help keep them at safe levels for your aquatic pals!

2- Additives: Another way to lower nitrate levels is to add supplements like Seachem Prime and Seachem Flourish, which contain beneficial bacteria in their formulas. These supplements will not only help lower nitrates but also improve your water quality by removing ammonia from your tank.

3- Reduce Lighting: Lighting can contribute to higher nitrate levels because it creates an environment that allows algae colonies to thrive, which produces more waste products such as nitrates than plants would produce on their own without lighting.

4- Unclean Water

If your fish are dying, it could be due to a dirty tank. If the water is not clean and free of disease-causing microorganisms, your fish may not survive. Even if they do live, they will likely have a shorter lifespan than one that lives in a cleaner environment. Poor water conditions can lead to stress on the fish which causes them to become weak and more susceptible to disease and parasites. Cleaner tanks mean healthier fish!

If you don’t change out the water often enough or if you add too many new fish into your tank at once, then these things can happen: You’ll have poor oxygen levels; there won’t be enough nutrients for all of the organisms living in your tank; there won’t be enough food for everyone; or some types of bacteria (such as gill flukes) might produce large amounts of waste products that pollute the water column by absorbing other nutrients from food sources (like algae).

5- Incompatible Tank Mates

neon tetras fighting over food

If your neon tetra is not growing, it may be due to the presence of other fish in your tank. Neon tetras are very sensitive to the environment and will grow slowly if they are being bullied by other fish. Neon tetras prefer to live alone and can become stressed if kept with other fish. If you have more than one neon tetra in a tank, they will fight constantly because they are territorial and each wants his own territory. Incompatible tank mates can cause stress that makes it difficult for them to grow properly.

6- Too Low Water Temperature

Neon tetras are tropical fish, meaning they require warmer water. The ideal temperature for your neon tetra should be between 65F and 80F. Neon tetras can live in temperatures from 60F to 86F (16C-30C) but are most comfortable when kept at the higher end of that range. If your tank is too cold, then your neon tetra will not grow properly nor will it thrive in its habitat.

7- pH Imbalance

unclean dirty fish tank

Your neon tetra’s growth could be slowed down by pH imbalance. pH is a measurement of the acidity or alkalinity of water, measured on a scale of 0 to 14, with 7 being neutral. The ideal bioload for your tank will depend on temperature, but most aquarists aim for a pH between 6.5 and 7.5 when they’re keeping tropical fish such as neon tetras in their tanks.

To check your tank’s pH level:

1- Buy some pH test strips (you can find them online or at pet stores). It doesn’t matter which brand you use, they all work the same way! Just make sure it says “aquarium” somewhere on the box so you know it’s safe for fish tanks (otherwise it might have chemicals that are harmful to aquatic life).

2- Wet one end of one strip with tap water from your aquarium and hold it up against a white background until both ends turn blue; this will let you know if there’s any kind of problem with what we call “hardness.” If not, then just go ahead and compare this color with another piece from another batch because sometimes they fade over time or get scratched up somehow during shipping.

8- Poor Diet

Another thing you should do if your neon tetra isn’t growing is to feed it better. The reason why this fish isn’t growing is that it’s not getting what it needs to eat. The best way to feed a neon tetra is by feeding them frozen blood worms or brine shrimp. These are both easy to find and can be found at most pet stores or online. If you decide to feed your neon tetra a different type of food, be sure that it is high in protein, omega-3 fatty acids, and calcium. Some examples of these foods include flake foods, pellets, and freeze-dried foods.

Here are a few tips to keep in mind while feeding your neon tetras:

  1. Feed your fish with a variety of foods.
  2. Don’t feed your fish the same food all the time.
  3. Don’t overfeed them.
  4. Don’t feed them anything that is not suitable for them (goldfish flakes or pellets).
  5. Don’t give them spoiled food as it will cause digestive problems and ultimately kill your fish.

9- Diseases

neon tetras best fish to have as pets

Diseases are the most common reason for a neon tetra not growing. The disease could be caused by another fish in your tank or it might be due to the water quality.

If you have more than one neon tetra and they all stop growing, it’s likely that they have come down with a disease. It’s important to isolate any sick fish so they don’t infect other healthy ones, but you also need to treat them with medication as soon as possible! If left untreated, some diseases can be fatal. especially if the infected fish is too weak to eat any medication offered by humans or other sources of food in your aquarium.

How To Make Your Neon Tetra Grow Bigger?

There is no hard and fast rule to make your neon tetra grow bigger but there are a few tips that you can follow to increase the chances of your neon tetra growing bigger.

1- Provide Quality Diet

Food has a direct relation with neon tetras growth. The best option is to feed them frozen bloodworms or brine shrimp. These are high-protein foods that will help them grow bigger and faster. If you aren’t able to provide these foods, then you should try feeding them some pellets such as spirulina algae pellets or live brine shrimp.

2- Regularly Change Water

The second thing that you need to do is add some clean water every day into your tank. This will help keep the pH levels stable and prevent any nasty diseases from spreading through your fish. However, make sure that you don’t overdo this because too much chlorinated water can harm your fish’s gills a little bit (which is why we suggest using carbon instead of chlorine).

3- Add Plants For A More Natural Habitat

Adding plants to the aquarium provides a more natural habitat for your neon tetra, which will make it easier for them to adjust to their new home. They not only like plants for cover but also because they provide food for the fish. Plants also help keep water quality high by absorbing nutrients from the water into their leaves or stems as they grow and die over time

4- Provide Stable Water Conditions

The health of your fish is also very important for their growth rate and overall health. You need to keep the water temperature at around 72 degrees Fahrenheit (22 degrees Celsius) as well as provide enough oxygen in the tank for them to breathe properly. You should also make sure that there are no harmful chemicals in the water because these can affect the growth rate of your fish as well as its lifespan.


Don’t worry if you find that your fish isn’t growing properly. These are some of the most common reasons why this happens and it doesn’t mean that your pet is unhealthy. It just means that you need to do more research on how to provide proper care for it!