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How Many Neon Tetras In A 30-Gallon Tank?

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Growing neon tetras in a tank of 30 gallons can be pretty convenient. The tank is pretty large and can accommodate a large school of these fish.

However, even a 30-gallon tank can become overcrowded, especially when adding large companions to your neon tetras.

In this article, I will walk you through the numbers, and explain how the calculation is made. So, without further ado, let’s dive into it.

How Many Neon Tetras In A 30-Gallon Tank?

In a 30-gallon tank, you can comfortably accommodate around 15-20 neon tetras.

This calculation considers the typical rule of one inch of fish per gallon of water, given that neon tetras grow to about 1.5 inches.

The presence of other fish species and the tank’s filtration quality can affect this estimation.

How Do You Calculate How Many Neon Tetras You Can Keep In A 30-Gallon Tank?

To calculate how many Neon Tetras you can keep in a 30-gallon tank, you can follow these steps:

  • Determine the space requirements: Neon Tetras require at least 1 gallon of water per 1 inch of adult fish. Since Neon Tetras typically grow to about 1.5 inches, you’ll need to allocate 1.5 gallons of water per fish.
  • Divide the total water volume by the space requirements per fish: Divide 30 by 1.5 to get the maximum number of Neon Tetras you can keep. The calculation would be: 30 / 1.5 = 20.
  • Be on the safe side: While 20 is the maximum, an ideal number would be something between 15 and 20, depending on your tank’s settings.

What Is the Recommended Tank Size For Neon Tetras?

Neon Tetras are small, schooling fish that prefer to live in groups, so they require some space to swim around comfortably.

A minimum tank size of 10 gallons is typically recommended for a small group of neon tetras.

However, a larger tank of 20 to 30 gallons would provide a better environment, especially if you plan to have a larger school of tetras or include other species.

Also Read: Neon Tetra Tank Size

Maintenance Tips And Tricks For A 30-Gallon Tank

Keeping neon tetras in 30 gallons is pretty straightforward, although I still recommend keeping eye on the following:

  • Regular Cleaning: Ensure your tank is cleaned regularly to remove waste or algae. This includes scrubbing the glass, substrate, and any decorations.
  • Water Change: Perform a 25%-50% water change every two weeks. This helps maintain water quality for your neon tetras and other aquatic inhabitants.
  • Filter Maintenance: Clean the filter monthly, but avoid cleaning it the same day as your water change to prevent shocking the fish.
  • Neon Tetra Diet: Feed your neon tetras a varied diet of high-quality flake food, freeze-dried, and live foods.
  • Monitor Water Parameters: Regularly check the pH, ammonia, nitrite, and nitrate levels. Neon tetras prefer a pH of 6.0-7.0 and require a tank with zero ammonia and nitrites.
  • Regular Observation: Keep a close eye on your neon tetras for any changes in behavior or appearance, which may be signs of stress or disease.
  • Adequate Lighting: Maintain a consistent light cycle to mimic the natural environment. Neon tetras usually require 10-12 hours of light per day.
  • Temperature Regulation: Keep the water temperature consistent, ideally between 70-81°F (21-27°C) for neon tetras.
  • Tank Mates: Choose tank mates carefully. Neon tetras are peaceful fish and should be paired with species of a similar temperament.

Also Read: How Many Neon Tetras In A 20-Gallon Tank?

What Will Happen If You Add Too Many Neon Tetras?

While a 30-gallon tank is a decent size for neon tetras, it is still possible to add too many of these fish, which can lead to serious issues:

  • Overcrowding: Adding too many neon tetras can lead to overcrowding, causing stress among the fish which can lead to disease or aggressive behavior.
  • Poor Water Quality: A high population of fish increases the amount of waste produced, which can quickly degrade water quality. Ammonia, nitrite, and nitrate levels can rise rapidly, harming or potentially killing neon tetras.
  • Insufficient Resources: With too many neon tetras, food might become scarce and not all fish will get enough to eat, leading to malnutrition or competition.
  • Oxygen Depletion: More fish means more oxygen consumption. Overcrowding can lead to insufficient oxygen levels in the water, stressing or suffocating the fish.
  • Disease Spread: If one neon tetra gets sick in an overcrowded tank, the disease can spread rapidly to the rest of the population.
  • Stress: Neon tetras are schooling fish and need space to swim. Lack of space due to overcrowding can stress them, leading to weakened immunity and a higher susceptibility to disease.
  • Inhibited Growth: In extreme cases of overcrowding, neon tetras’ growth may be stunted due to stress and inadequate resources.

Also Read: How Many Neon Tetras In A 40-Gallon Tank?

Does The Gender Of The Neon Tetras Matter?

No, the gender of neon tetras does not matter when deciding the number of neon tetras for a 30-gallon tank.

Both male and female neon tetras have similar sizes and space requirements, so you would calculate their needed space in the same way.

The most important factor is to avoid overcrowding and to ensure adequate conditions for each fish, regardless of gender.

Will The Tank Become Overcrowded Due To Breeding?

No, it’s unlikely that a 30-gallon tank will become overcrowded due to breeding.

Although neon tetras can reproduce, they don’t breed easily, especially in a community tank setting.

Furthermore, 30 gallons offer ample space for a reasonable number of neon tetras, even considering potential offspring.

Can You Breed Neon Tetras in a 30-Gallon Setup?

Yes, you can comfortably breed neon tetras in a 30-gallon setup. Here are some tips:

  • Separate Breeding Tank: It’s often best to set up a separate breeding tank, although a 30-gallon tank can provide enough space for breeding while housing other fish.
  • Water Conditions: Neon tetras prefer slightly acidic water for breeding (pH around 5.5-6.0) and a temperature around 77°F (25°C).
  • Mating Pairs: Introduce a balanced number of males and females to the breeding tank. Typically, a ratio of two females to one male is ideal.
  • Diet: Feed the neon tetras a high-quality diet, including live food, to encourage breeding.
  • Low Lighting: Keep the lighting low or use floating plants to dim the tank as neon tetras prefer a dimly lit environment for spawning.
  • Spawning Sites: Provide fine-leaved plants or a spawning mop as neon tetras scatter their eggs on such surfaces.
  • Post-Spawning: After spawning, remove adult neon tetras to prevent them from eating the eggs.
  • Care for Fry: Once the eggs hatch, the fry should be fed infusoria or commercial fry food until they can eat larger food.

How Often Do Neon Tetras Breed?

Neon tetras can breed every one to two weeks under optimal conditions, including factors like appropriate diet, water parameters, and environmental conditions.

However, successful breeding in a home aquarium can be challenging due to their specific requirements.

Is It Possible To Add More Neon Tetras To A 30-Gallon Tank?

Indeed, you can keep more than 20 neon tetras in a 30-gallon tank, although it’s important to make some adjustments to maintain a healthy environment:

  • Upgrade Your Filtration: Invest in an advanced filtration system that can deal with a larger bioload, ensuring your neon tetras have clean water.
  • Test Water Regularly: With more fish, changes in water chemistry, including ammonia, nitrite, and nitrate levels, can occur more rapidly. Frequent testing, perhaps twice a week, can help spot any issues early.
  • Increase Water Changes: Aim for changing about 30-50% of the water weekly, rather than the standard 25%, to help keep the environment clean for your neon tetras.
  • Keep a Close Eye: With more neon tetras, it’s essential to regularly observe their behavior. Signs of stress can indicate that the tank is becoming overcrowded and action may need to be taken.

How Many Neon Tetras Should Be Kept Together Generally?

Neon Tetras are social fish that thrive in groups.

It is recommended to keep them in schools of at least 6 to 10 individuals to ensure their well-being and allow them to display their natural behaviors.

In larger aquariums, it’s advantageous to keep them in even larger groups as this helps reduce stress and enhances their vibrant coloration and lively behavior.

Keeping Neon Tetras With Other Fish In A 30-Gallon Tank

The good news is that 30 gallons offer plenty of space for neon tetras and other companions. Here is a table I created that discusses the most common tank mates:

Tank MatesQuantity (in 30 gallons)
Only Neon Tetras15-20
Neon Tetras & Guppies15 Neon Tetras, 10 Guppies
Neon Tetras & Mollies15 Neon Tetras, 5-6 Mollies
Neon Tetras & Zebra Danios15 Neon Tetras, 15 Zebra Danios
Neon Tetras & Platy Fish15 Neon Tetras, 10 Platy Fish
Neon Tetras & Betta Fish15-20 Neon Tetras, 1 Betta Fish

1. Neon Tetras And Guppies

In a 30-gallon tank with guppies, you could comfortably keep around 15 neon tetras and 10 guppies, given that guppies grow to be around 2 inches in length and require similar care conditions as neon tetras.

2. Neon Tetras And Mollies

For a tank with both neon tetras and mollies, you could keep about 15 neon tetras and 5-6 mollies, considering that mollies are larger (up to 4 inches) and need more space.

3. Neon Tetras And Zebra Danios

If you want to keep neon tetras with zebra danios, a 30-gallon tank could house around 15 of each species. Both fish are similar in size and have comparable environmental needs.

4. Neon Tetras And Platy Fish

In a tank with platy fish, you could house around 15 neon tetras and 10 platy fish. Platies are slightly larger than neon tetras but have similar care needs.

5. Neon Tetras And Betta Fish

Lastly, for a 30-gallon tank with a betta fish, you could keep one betta along with 15-20 neon tetras, as bettas are solitary fish that require less space, but their aggressive nature should be considered when adding other fish.


A 30-gallon tank is large enough to accommodate a school of 15-20 neon tetras, which is a decent group size for this type of fish.

You can easily introduce other species as well, including mollies, guppies, zebra danios, and even betta fish.

Just make sure not to overcrowd your tank and perform regular water changes.