Neon Tetra Eggs Hatching Time: Everything You Need To Know

Disclosure: When you purchase something through my affiliate links, I earn a small commission. As an Amazon Associate, I earn from qualifying purchases.

The appearance of neon tetra eggs raises many questions, with the most common being how long it takes for them to hatch

That was exactly what I was wondering when I first encountered them.

I had no idea how much time was considered too long, and when I should give up on hatching the current batch.

In this article, I will address both of these questions and provide step-by-step instructions on what to do if the eggs don’t hatch within the expected timeframe. Let’s dive right in.

Also Read: Neon Tetra Eggs 101

How Long Does It Take For Neon Tetra Eggs To Hatch?

Neon tetras eggs typically hatch within 24 to 36 hours:

  • Day 1: Neon tetras lay their eggs. The female can produce up to 200 eggs during this period.
  • Within a few hours of being laid: The eggs should be fertilized by the male. If they are not fertilized quickly, they will likely die and not develop into viable embryos.
  • 24-36 hours post-fertilization: If kept at an optimal temperature of around 77-80 degrees Fahrenheit (25-27 degrees Celsius), the eggs will begin to hatch into fry (baby fish).

After that, you can expect the following development process in the newborn fry:

  • 1 week post-hatching: At this point, the fry should have absorbed their yolk sacs and begin to search for food. Feed the fry with food small enough for them to eat, such as infusoria or commercially available fry food.
  • 2-3 weeks post-hatching: The fry start to develop the distinct coloration of neon tetras, although they are still small and not fully formed.
  • 6-8 weeks post-hatching: The fry should now resemble miniatures of the adult fish, displaying full neon colors and able to eat the same diet as the adults. At this stage, they can be gradually introduced to the main tank if they were separated for growth and safety.

Also Read: How Many Eggs Do Neon Tetras Lay At A Time?

Why Are My Neon Tetra’s Eggs Not Hatching In Time?

Ordinarily, neon tetra eggs should not take more than two days to hatch.

If you’ve waited more than two days and don’t see any fry, you may need to consider several potential issues:

1. The Eggs Are Not Fertilized

  • Neon Tetras fertilize externally and improper timing or lack of males can lead to unfertilized eggs.
  • Sub-optimal water conditions, stress factors, or not meeting specific breeding requirements like low light and soft water can hinder successful breeding.

You can address these problems by enhancing the tank’s conditions. These are considered optimal for breeding neon tetras:

  • Temperature: 72-78° F (22-25° C)
  • pH: 6.0-7.0
  • Hardness: 1-2 DH (18-36 ppm)
  • Ammonia: 0 ppm
  • Nitrites: 0 ppm
  • Nitrates: <20 ppm

To monitor the pH, ammonia, nitrates, and nitrites levels, I personally recommend using the API FRESHWATER MASTER TEST KIT (link to Amazon).

2. The Eggs Have Been Infected With Fungus

It is pretty known for neon tetras eggs to catch fungus, consider the following:

  • Fungal infections, often turning eggs white or fuzzy, are common and can be triggered by poor water quality or unfertilized eggs.
  • Rapid spread of fungus mandates regular monitoring and removal of infected eggs. Using fungicides and maintaining stable water conditions can prevent these infections.
  • Providing a suitable environment including low light and a breeding mop or dense plant cover can prevent fungal growth.

What Should I Do If The Eggs Don’t Hatch?

1. If the Eggs Are Not Fertilized

  • Check the Male to Female Ratio: Ensure there are enough males to fertilize the eggs. A ratio of one male to two females is often recommended.
  • Check Fish’s Age and Health: Ensure that the males are neither too young nor too old, and they’re in good health. A poor health condition can affect their fertility.
  • Optimize Water Conditions: Maintain optimal water conditions – soft, slightly acidic water, with a temperature around 75-80°F (24-27°C) is ideal.
  • Reduce Stress: Ensure the fish aren’t stressed due to overcrowding, aggressive tank mates, or poor diet. Provide sufficient hiding places and keep the tank environment calm.
  • Create a Conducive Breeding Environment: Use low light and provide dense plant cover for ideal breeding conditions.

2. If The Eggs Have Been Infected With Fungus

  • Identify the Infected Eggs: Look for eggs that have turned white or fuzzy. These are indicators of a fungal infection.
  • Remove Infected Eggs: Carefully remove any eggs that show signs of fungal infection to prevent it from spreading to the rest of the clutch.
  • Use a Fungicide: Consider adding a safe, aquarium-approved fungicide to the water to prevent further fungal growth.
  • Improve Water Conditions: Regular water changes, temperature stability, and ensuring suitable water parameters can help prevent infections.
  • Enhance Breeding Environment: Provide a suitable environment with dense plant cover or a breeding mop, along with low light conditions, to deter fungal growth.

Also Read: What To Do When Neon Tetras Lay Eggs?


If you are in a rush, here is a quick summary of what I discussed earlier:

  • Neon tetra eggs typically hatch within 24 to 36 hours after being laid if they are fertilized and kept at an optimal temperature.
  • The development process of neon tetra fry involves absorbing yolk sacs, searching for food, developing coloration, and resembling miniatures of adult fish over several weeks.
  • If neon tetra eggs do not hatch within the expected timeframe, potential issues such as unfertilized eggs, sub-optimal water conditions, or fungal infections should be considered.
  • Addressing problems with fertilization, water conditions, and breeding requirements can improve the chances of successful hatching.
  • Dealing with fungal infections requires identifying and removing infected eggs, using a fungicide, improving water conditions, and creating a suitable breeding environment.