How many neon tetras can be kept in a 55 gallon tank

How Many Neon Tetras Can Be Kept in a 55-Gallon Tank?

Due to their natural red and blue colors, neon tetras are a popular option among people who like to rear ornamental fish . They are suitable for your home or any environment where you want the relaxing effect of having fish around you constantly. A 55 gallon tank is one of the options that enthusiasts may consider when creating a suitable habitat for their neon tetras and this article will let you know how many fish can be accommodated in that space.

How many neon tetras can be kept in a 55 gallon tank? The quick answer is that a 55 gallon tank can accommodate around 28 to 50 neon tetras. For a more detailed answer – keep reading!

Neon tetras are energetic fish, so they are fun to watch. They are usually compatible so you won’t get the disharmony in the tank, that can be displayed with some other species. These animals are schooling fish, so it’s not usually recommended that you put just one or two in a tank. This is where a 55 gallon tank is ideal because it can easily house several of these peaceful fish, in a variety of water parameters.

How Many Neon Tetras in A 55 Gallon Tank? - Estimate the Bio Load

When considering the bio load of fish, you’ll need to think about their length, aggression and other characteristics, such as their swim room. This article will discuss those factors in more detail and make a recommendation on the number of fish that you can comfortably keep in a 55 gallon tank.

The amount of waste that they produce is also a consideration and this factor makes neon tetras easier to plan for, in terms of the space that they require, than other species. Neon tetras have a small bio load so they have moderate filtering needs. A 25% water change each week in your 55 gallon tank will be sufficient, while their waste will be manageable as long as you don’t overfeed.

Neon Tetras Prefer Space

Neon tetras are shoaling fish, so they do not like being forced within a compact area. Bear in mind that a larger school will display more activity than a school that is smaller. They like the freedom of being able to move around in any direction they choose. Since they move as a group, the tank that they are in should provide adequate space on all sides of the group of fish as they swim together.

If you have lots of tetras, you’ll need a big tank. Never put a set of 15 fish in a 5 gallon tank. They should not feel as if they are about to bounce into each other due to their enforced proximity in a tank that’s too small.

Neon Tetras Prefer Space

Calculate for the Growth of Your Fish

If you get your neon tetras when they are small, your tank may seem to be too big for them. However, you shouldn’t let their current size give you a false impression. Most neon tetras will grow to at least 1.5 inches long and some may even reach two inches when they are fully grown.

(Check out our article How To Care For Neon Tetras for more info on neon tetra care!)

Rule of Thumb for Tank Selection

Whether you’re purchasing a 55 gallon tank now because you suspect that your tetras are feeling uncomfortable or you want one because you hope to get more fish at another point, there’s a rule of thumb that you can use to ensure that you’re getting a tank that will be ideal.

Generally, you’ll need one gallon of water for every inch of fish. If you only had five fish and each of them was two inches long, you would have to provide enough room for 10 inches of fish. That means you would need at least 10 gallons of water for them to live in.

That 10 gallons of space would be adequate if there was nothing else in the tank. However, that’s not often the case. Most people have decorations in their tank and this would cut down on the space that’s available for their fish to swim in. Consider the amount of space that is used by other objects in the tank, such as driftwood, when you want to make sure your fish have enough room. You may need to make sure three of four extra gallons of water are provided for your five fish.

how many neon tetras in a 30 gallon tank

Large Area Covered

If you need a tank that will cover a large area, a 55 gallon tank is a good choice. This is bigger than a 50 gallon tank, so it can easily hold between 28 and 50 tetras of various sizes. The maximum would work in a situation where some of your fish are just around 1.4 inches. These 55 gallon tanks are a popular option for fish owners and you may have even seen a captivating school of neon tetras in one of them in someone else’s home, or even in a busy community center. While they are big, 55 gallon tanks are quite affordable so you can keep your pet fish comfortable without breaking your budget.

A 55 gallon tank is wider than several other fish tanks, so your neon tetras will have enough horizontal swimming space to suit their needs. They also offer more height than some of the other fish tanks that are on the market. The height makes these tanks suitable for neon tetras, since these fish like to swim on the top deck and in the middle of their tank.

If you choose to go with the minimum and have just 28 neon tetras in a 55 gallon tank, you will have enough room to add a few live plants. Live plants go very well with neon tetras and the effect is beautiful. Bear in mind that if you only have 28 or 30 in your 55 gallon tank, it will be easy to notice if one of them is ill. The task of monitoring them becomes harder when you have 40 neon tetras, even though that number can hold in your 55 gallon tank.

Small Tanks are Not Ideal

Young fish need plenty of room to swim and develop properly. If you have your fish in a tank that is too small, they may develop spinal deformities problems with bone development and even look stunted. Since they won’t be able to use their muscles fully because of the tight space that they are forced to be in, those muscles will slowly start to atrophy.

Your fish need to develop[ fully and they need to exercise enough, even if you get them as adults. If they can’t swim around feely, their overall health will suffer. Eventually, your neon teras will not survive. You’ll find that tetras forced into a tank that is too small, have a shorter life span than those in a 55 gallon tank or another tank that provides adequate room.

If you have around 35 neon tetras in a 55 gallon tank, they will all have enough space. That will be a beautiful school of fish and they will thrive in the space. If you have 30 or 40 neon tetras swimming around in your 55 gallon tank, you will have a beautiful array of color schooling and moving from one point to another in your tank. It will be soothing to have that near you each day.

Small tanks are not ideal for keeping Neon Tetras

Although the rule of thumb describes the minimum space required for neon tetras, you should not restrict your fish to tanks of this size. if possible, you should always try to provide more space than the minimum, even when you have calculated for decorations in the tank. For example, if you have 10 fish and calculate that this could be up to 20 inches of fish, they will need at least 20 gallons of water.

If objects are in the tank, you may need at least 9 gallons of water in addition to the initial 20 gallons, to accommodate them. However, even that would be the minimum. A 29 gallon tank would be a tight fit. A 30 gallon tank or higher would be better.

Tanks that are too small make it hard to stabilize the environment for the number of fish that you have. If you are just beginning, with your very first aquarium, you may be tempted to think that a smaller aquarium would be easier to manage than a 55 gallon tank but that is not the case.

Small tanks are not ideal for beginners since they do not give you much room to make mistakes. You cannot easily adjust the environment in a small tank to make it better for your neon tetras. If you try to squeeze an extra fish or two in the tank, you will have to pay more attention to ensuring that you clean the tank often. You’ll also have to pay attention to the overall health of your fish.


A 55 gallon tank can comfortably house between 28 and 50 neon tetras of different sizes. Ensure that you are willing to dedicate the time for each fish in your school and you’ll have happy, healthy fish for a long time. Choosing the right size tank provides enough room for growth and this is one of the reasons why many people like a spacious option like the 55 gallon.