How to Successfully Raise Goldfish Fry?

Raising goldfish fry can be an exciting and rewarding experience for any fish keeper. However, it can also be challenging if you don’t know the right techniques and methods to ensure the health and survival of the fry. In this article, I’ll share my personal experience and expert tips on how to successfully raise goldfish fry. Read on to learn more.

Things to do After Successful Spawning

Congratulations! Your goldfish have successfully spawned and you now have a batch of tiny fry swimming around. But what’s the next step? Here are some things to do after successful spawning to ensure the health and growth of your goldfish fry:

Provide a Safe and Isolated Environment

Goldfish fry can be very delicate and vulnerable in their early stages, and they need a safe and isolated environment to grow and develop properly. You can either use a separate breeding tank or a fry trap inside your main tank with an air stone for oxygenation. Make sure to keep the water clean by doing daily water changes, and avoid using any chemical treatments that could harm the fry.

Feed Properly and Frequently

Goldfish fry have very small stomachs and need to be fed frequently throughout the day. Start by feeding them newly hatched brine shrimp or commercially available fry food, and gradually move on to more solid foods as they grow. You can also crush up flakes or pellets into tiny pieces for easier consumption.

Watch for Signs of Illness or Stress

Goldfish fry are susceptible to diseases and stress, so it’s important to keep a close eye on them and watch for any signs of illness, such as lethargy, loss of appetite, or fins clamped to the body. Early detection and treatment can prevent the spread of illness and potentially save your fry.

Gradually Introduce More Space

As your goldfish fry grow and develop, you can gradually introduce them to more space. When they reach about an inch in length, you can move them to a bigger tank with a filtration system. However, be careful not to overcrowd the tank and provide enough hiding spots and territories for all fish.

Ideal Temperature for Hatching the Eggs

Goldfish typically spawn in the spring and summer months when the water temperature is warmer. The ideal temperature for hatching goldfish eggs is between 68 to 74 degrees Fahrenheit (20 to 23 degrees Celsius).

If you’re planning to breed goldfish, it’s important to ensure the water temperature is within this range. You can use a thermometer to monitor the temperature or a heater with a thermostat to maintain a consistent temperature.

Keep in mind that the temperature may vary depending on the specific goldfish species. Some species may prefer slightly warmer or cooler water for breeding, so it’s important to do your research on the specific species you plan to breed.

Additionally, it’s important to make sure the temperature is consistent throughout the breeding tank. Installing a heater with a circulation pump can help to distribute the heat evenly and avoid any temperature fluctuations.

If the water temperature is too high or too low, it can negatively affect the hatching and development of the eggs. High temperatures can cause the eggs to hatch too quickly, while low temperatures can slow down the hatching process or even stop it altogether.

Overall, maintaining the ideal temperature for hatching goldfish eggs is crucial for a successful breeding experience. Make sure to monitor the temperature regularly and provide a consistent, safe, and healthy environment for your goldfish to thrive.

Agitate the Water with Aeration

When breeding goldfish, it’s important to ensure that there is enough oxygen in the water for the fry to survive. Goldfish eggs and fry require high levels of oxygen to develop properly. One way to ensure adequate oxygen levels is to agitate the water with aeration.

Aeration is the process of adding air to the water to increase its oxygen content. There are several ways to agitate the water with aeration, including:

  • Air Stones: These small devices are connected to an air pump and placed at the bottom of the tank. The air stone releases tiny bubbles that agitate the water and add oxygen to it.
  • Sponge Filters: Sponge filters are another way to agitate the water with aeration. These filters use a sponge material to trap debris and promote the growth of beneficial bacteria, which helps to break down waste and increase oxygen levels.
  • Powerheads: Powerheads are water pumps that create water flow and agitation, similar to the currents in a river. These can be beneficial for goldfish fry as they can swim against the current to build up strength and exercise.

By agitating the water with aeration, you can ensure that your goldfish eggs and fry are getting enough oxygen to develop properly. Keep in mind that while aeration is important, you don’t want to create too much agitation as this can stress out the fish.

It’s also important to regularly monitor the oxygen levels in the water and adjust the aeration as needed. Installing a dissolved oxygen meter can provide accurate readings of the oxygen levels in the water and help to prevent any potential oxygen deficiencies.

Prevent Fungus and Bacteria Growth

When breeding goldfish, it’s important to prevent the growth of fungus and bacteria in the water as these can be harmful to your goldfish eggs and fry. Here are some tips to prevent fungus and bacteria growth:

Keep the Water Clean

One of the best ways to prevent the growth of fungus and bacteria is to keep the water clean. This means doing regular water changes to remove any waste and debris that can create a breeding ground for harmful microorganisms. Aim to do a water change of 10-20% daily to ensure the water in the breeding tank is clean and healthy.

Avoid Overfeeding

Overfeeding is another common cause of fungus and bacteria growth in fish tanks. Excess food can rot and decay, creating an environment for harmful microorganisms to grow. To prevent overfeeding, only feed your goldfish fry small amounts of food several times a day. Avoid leaving uneaten food in the tank for too long and remove any excess food as soon as possible.

Use Fungus and Bacteria Treatment

If you notice any signs of fungus or bacteria growth in the tank, such as white cotton-like strands on the eggs or fry, or strange smells coming from the water, it’s important to take action immediately. You can use a fungus or bacteria treatment from your local pet store, but make sure to follow the instructions carefully and avoid using any harmful chemicals that can harm your goldfish fry.

By following these tips, you can prevent the growth of fungus and bacteria in your goldfish breeding tank and ensure that your eggs and fry are healthy and thriving.

Egg Development and Hatching

The development and hatching of goldfish eggs typically take place within 4 to 7 days, depending on the water temperature. Here are the stages of egg development:

1. Fertilization

After spawning, the male goldfish will fertilize the eggs that have been laid by the female. The eggs will then attach to the surface of plants or substrate in the breeding tank.

2. Embryonic Development

Within a few hours, the eggs will start to develop noticeable features, such as the eyes and spinal cord. The eggs will continue to grow and change in appearance over the next few days.

3. Hatching

Once the eggs are fully developed, they will start to hatch. The fry will start to wiggle and move inside the egg, and the egg membrane will start to break down. After a few hours, the fry will emerge from the egg and start swimming around in the tank.

During the egg development and hatching process, it’s important to maintain the ideal water temperature and provide enough oxygen and food for the eggs and fry to develop properly. Keep a close eye on the eggs and remove any unfertilized or dead eggs that can harm the healthy ones.

By understanding the egg development and hatching process, you can better prepare and adjust your breeding tank to ensure the best possible outcome for your goldfish eggs and fry.

Free Swimming Fry Care

Once the goldfish fry are free swimming, they require more care and attention to ensure their healthy development. Here are some tips for caring for free swimming fry:

Provide a Balanced Diet

As the fry grow, their dietary needs will change. It’s important to provide them with a balanced diet that includes a variety of foods such as newly hatched brine shrimp, commercially available fry food, and crushed pellets or flakes. Be sure to feed them small amounts several times a day to avoid overfeeding and wasting food.

Maintain Clean Water

Just like with egg development, clean water is crucial for the development and survival of free swimming fry. Do regular water changes of 10-20% to maintain good water quality. Avoid using any chemicals or treatments that could be harmful to the fry.

Observe Behaviour

Observe the behaviour of your goldfish fry regularly. They should be swimming actively and exploring their surroundings. If you notice any signs of illness or stress, such as lethargy or a loss of appetite, it’s important to take action immediately and isolate the affected fish.

Avoid Overcrowding

As the fry grow, it’s important to avoid overcrowding the tank. Provide them with enough space and hiding spots. When they reach approximately 1 inch in length, move them to a bigger tank with a filtration system to maintain good water quality.

Feeding Goldfish Fry

Feeding goldfish fry can be tricky, as they have very small mouths and require frequent feedings throughout the day. Here are some tips for feeding goldfish fry:

Newly Hatched Brine Shrimp

Newly hatched brine shrimp is a common and nutritious food for goldfish fry. These tiny organisms are rich in protein and essential nutrients that promote healthy growth. You can purchase newly hatched brine shrimp from your local pet store or hatch them at home using brine shrimp eggs and a special hatchery kit.

Commercially Available Fry Food

There are many commercially available fry foods that are specially formulated for the dietary needs of goldfish fry. These foods come in a variety of forms such as powder, pellets, or flakes. Look for a food that is high in protein and essential nutrients. Start with a small amount and gradually increase as the fry grow.

Crushed Pellets or Flakes

If you have adult goldfish in your tank, you can crush up their food into very tiny pieces for the fry. Be sure to avoid any food that is too large or could cause choking or blockage in their digestive system.

Avoid Overfeeding

Overfeeding can be harmful to goldfish fry, as excess food can rot and decay, causing water quality issues and health problems. Feed small amounts several times a day and remove any uneaten food as soon as possible.

Goldfish Fry Tank Maintenance

Maintaining a clean and healthy environment in your goldfish fry tank is crucial for their survival and growth. Here are some tips for goldfish fry tank maintenance:

Daily Water Changes

One of the most important aspects of goldfish fry tank maintenance is daily water changes. Doing a 10-20% water change every day will help to remove any waste or debris that can harm the fry. Use a siphon to remove debris from the substrate, and avoid overcrowding the tank with too many fry.

Filter Maintenance

If you have a filtration system in your goldfish fry tank, it’s important to maintain it regularly. Clean the filter media at least once a week, and replace it every 2-3 months. Avoid using a filter that creates too much water flow, as this can stress out the fry.

Temperature and Oxygen Levels

Maintaining the ideal water temperature and oxygen levels is crucial for goldfish fry tank maintenance. Use a heater with a thermostat to maintain a consistent temperature, and use an air stone or other aeration device to ensure adequate oxygen levels.


Observing your goldfish fry regularly is important for keeping up with tank maintenance. Look for any signs of illness or stress, such as lethargy, loss of appetite, or unusual behavior. Early detection of health issues can prevent further problems down the line.

Culling the Goldfish Fry

Culling is the process of removing weaker or deformed goldfish fry from the breeding tank to allow the stronger and healthier fry to grow and develop properly. Although it can be difficult, culling is an important part of goldfish breeding and is necessary for the overall health and quality of the fry.

Here are some tips for culling goldfish fry:

Wait Until They Are Large Enough to Identify

It’s important to wait until the fry are large enough to identify before culling them. This typically occurs when they are around 6-8 weeks old and have reached 1-2 inches in length. This allows you to better identify any deformities or abnormalities.

Use a Catching Net

To cull the fry, use a small net to catch them one at a time. Examine each fry carefully to determine if there are any deformities or weaknesses that could affect their growth or survival.

Dispose of Humanely

Once you have identified the weaker or deformed fry, dispose of them humanely. Some options include using clove oil, freezing, or using a chemical euthanasia solution according to instructions. Be sure to follow proper disposal procedures for any dead fry.

Culling can be a difficult and emotional process, but it’s necessary for the overall health and quality of the fry. By identifying weaker or deformed fry and removing them from the breeding tank, you’re giving the stronger and healthier fry a better chance to grow and thrive.


Raising goldfish fry can be a challenging but rewarding experience for any fish keeper. By providing a safe and healthy environment, maintaining proper feeding and tank maintenance, and following expert tips for breeding and culling, you can successfully raise goldfish fry into healthy and vibrant adult fish. Do you have any tips or tricks for raising goldfish fry? Leave a comment below!

Updated: May 5, 2023

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