Do Neon Tetras Need a Filter?

Are you setting up a new aquarium for your beautiful neon tetras? If so, you’re probably wondering, do neon tetras need a filter?” The answer is yes. A filter is an important part of the neon tetras’ tank for many reasons, from oxygenation to temperature regulation.

Read on to learn all about the advantages of installing a filter in your tank, the ideal type of filter for neon tetras, and the conditions under which these fish can survive without filters.

Do Neon Tetras Need a Filter?

Neon tetras do need a filter in their tank, especially if their keeper is a beginner. Filters remove toxins, regulate the temperature, aerate the tank, and allow for the propagation of good bacteria.


The main job of a filter is to clean the water and remove harmful toxins. This creates a cleaner environment for your neon tetras.

Like all living organisms, fish produce waste, which can contaminate the water and pollute the entire tank. This is what makes a filter one of the first requirements of any tank.

On top of that, filters also help maintain the tank’s pH level, which is an important factor for the growth and happiness of neon tetras.

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Temperature Regulation

Installing a filter in your neon tetras tank helps regulate the temperature of the tank. Filters help tank heaters by creating water currents.

In other words, the filter circulates water, which helps spread the heat to every part of the tank. This helps maintain a certain temperature, which can be paramount to the growth of your neon tetras.

Aeration and Oxygenation

Filters are a great means of aeration and oxygenation of tanks. Typically, filters pump water onto the tank’s surface. This causes the circulation of water, which allows the water at the bottom of the tank to move to the surface.

In addition, you may attach a spray bar aerator to your filter to reach the blind spots in your tank. This little attachment allows further surface agitation and aeration.

Propagation of Beneficial Bacteria

Not all bacteria are harmful. In fact, some bacteria types are required in certain environments. For instance, some beneficial bacteria grow in fish tanks and actually help fish thrive.

Beneficial bacteria colonize everything in the tank, from plants to decorations. They colonize the filter media and help keep the tank water suitable for fish for a long period.

These beneficial bacteria, such as Nitrosomonas and Nitrobacter, break down the nitrate and ammonia in water. This means that the presence of a filter provides a good flow of water inside the tank.

What Type of Filter Suits a Tank of Neon Tetras?

Generally speaking, neon tetras are small fish with little waste, so they don’t cause much contamination to their tanks.

On that account, internal filters can be ideal for the job. They use different filtration media and provide moderate water circulation with their electric pumps.

An important aspect to remember here is that neon tetras are tropical fish that generally live in slow water. This is why a stronger filter won’t be suitable for them.

On top of that, internal filtration systems take advantage of mechanical and biological media, which makes them highly efficient. Internal filters are also economical and cheap; they don’t consume much power.

These filters can replace the tank’s CO2 with oxygen via surface agitation, as they circulate the water and cause a mild current that is suitable for your pretty neon tetras.

Water circulation is crucial for your tetras’ well-being. It allows the water to enter the blind spots within a tank. Such blind spots don’t get enough oxygen and trap dirt, which can be dangerous for your tetras.

Can Neon Tetras Survive Without a Filter in Their Tank?

Although filters are important in a neon tetra tank, the fish’s survival doesn’t really depend on them. This means that under certain circumstances, neon tetras can survive without filters.

However, it all depends on the fish keeper. For instance, an expert fish keeper may be able to maintain his/her tank without filters, but is not something a novice should even try.

Two Neon Tetras

How to Maintain Your Neon Tetras Tank Without a Filter?

Certain conditions are necessary for the optimum growth of neon tetras. If you can manage to maintain the following factors, your neon tetras can survive without a filter.

  • Tank Size: Without a filtration system, it’s recommended that you choose a large tank. This gives you enough room to grow enough plants for natural filtration.
  • Nitrogen Cycle: Perform a full nitrogen cycle before beginning your fish home.
  • Extra Substrate: Place 3-4 inches of substrate in your tank to host beneficial bacteria for filtration.
  • Live Plants: Live plants can be a natural source of filtration, so make sure you place plenty of them in your tank.
  • Water Changes: Regularly perform partial changes for the water in your tank. It’s recommended that you do it weekly in the case of a non-filtered neon tetras tank
  • pH Level: neon tetras prefer acidic water with a pH between 5.5 and 6.8. You can check the pH using pH testing strips. Add a bag of organic peat or sphagnum moss to your tank in order to soften the water and lower the pH level whenever necessary. Remember to replace it every now and then
  • Dim Lights: In their natural habitat, neon tetras live in dark waters. So, it’s recommended that you dim the lights to mimic their natural habitat, which helps them thrive.


Do neon tetras need a filter? Yes, they do, but they still can live without one, though we wouldn’t recommend even trying unless you’re an advanced fish keeper.

Filters are important because they clean the tank, oxygenate the water, regulate the tank’s temperature, and propagate beneficial bacteria.

However, if you’re an expert fish keeper, you’d know how to maintain your neon tetras without a filter in their tank.