Recommended Containers for Raising Medaka: Aquarium, Styrofoam, Plastic Cases, Pots, and Planters?

Recommended Containers for Raising Medaka: Aquarium, Styrofoam, Plastic Cases, Pots, and Planters?

In this article, I will introduce the recommended containers for raising medaka. You can raise them in aquariums, styrofoam, plastic cases, pots, and planters, but which one is the best?

Choose Containers with a Capacity of 10 Liters or More

First, to get straight to the point, any container that can hold water is suitable for raising medaka. However, it’s best to use a container with a capacity of 10 liters or more.

Specifically, if you are raising them indoors, an aquarium like the one shown above is sufficient.

This is because smaller water volumes lead to quicker water pollution, making medaka more susceptible to diseases. Specifically, with a container capacity of 10 liters or more, the frequency of water changes can be reduced, and the risk of diseases is also lower. Therefore, I always use containers with a capacity of 10 liters or more for raising medaka.

Choose Durable Containers for Outdoor Use

Additionally, when raising medaka outdoors, it’s important to choose containers that are resistant to deterioration. Cheap plastic containers, especially transparent ones, can easily degrade and break due to UV exposure. Be particularly careful with transparent storage boxes as they can crack and break quickly under UV exposure.

Recommended Containers for Raising Medaka

Here are the recommended containers for raising medaka that I actually use.


Link to Aquarium on Amazon

If you are raising medaka indoors, the best container is an aquarium. Aquariums for tropical fish or goldfish are available at home improvement stores and can be purchased anytime.

The reason why an aquarium is the best choice among medaka raising containers is that it allows easy observation from the side. If you raise medaka in tubs or storage boxes, you can’t observe them from the side, and it’s often difficult to notice diseases. On the other hand, an aquarium has glass on all four sides, so you can quickly notice any abnormalities in your medaka.

However, aquariums are the most expensive and heavy among medaka raising containers, making them difficult to move once set up. Therefore, it’s challenging to use aquariums for all medaka containers.

That’s why I use aquariums only for breeding stock and other containers like storage boxes for the rest. Since breeding stock needs to lay eggs, daily health checks are necessary. It’s best to raise important individuals in an aquarium.

All-glass aquariums are aesthetically pleasing as interior decorations but are heavy and hard to move. For raising medaka, framed aquariums (standard commercially available ones) are recommended.

Daiso Square Storage Box

The Daiso Square Storage Box is the next best container after aquariums for raising medaka. I have been using dozens of them in total. The Daiso Square Storage Box is a large 15-liter container for only 200 yen.

Moreover, it comes in dark gray and brown colors, so the medaka’s colors do not fade. It’s also very durable and can be used outdoors without any issues. Even under the scorching summer sun, the container did not deteriorate. I currently use the square storage box as a fry container. The 15-liter container for 200 yen is extremely convenient and cost-effective.

Link to Daiso Square Storage Box

Plastic Cases (Breeding Cases)

Link to Plastic Breeding Case on Amazon

Plastic cases (breeding cases) are containers designed for raising beetles and other creatures. They are available for a few hundred to about a thousand yen, roughly half the price of an aquarium.

Plastic cases come in various sizes: mini, small, medium, large, and extra-large. I recommend buying a medium-sized one (7 liters or more). I used to use medium-sized plastic cases for raising medaka fry, but they felt a bit small, so I no longer use them. However, I still use the super extra-large size (35 liters). For raising medaka, the large size (13 liters) or extra-large (25 liters) are particularly recommended.

Storage Boxes

Storage boxes are also recommended for raising medaka. However, if you place transparent storage boxes outdoors, they will quickly degrade due to UV exposure, so they are better suited for indoor use.

Daiso sells 10-liter storage boxes for 300 yen and 20-liter ones for 400 yen, which I currently use for raising fry. Additionally, because they are semi-transparent, you can observe the medaka from the side, making them excellent raising containers.

Link to Daiso Storage Boxes


Link to Plastic Tub on Amazon

If you are raising medaka outdoors, plastic tubs are highly recommended. They are durable and do not degrade outdoors like storage boxes. Therefore, tubs are the best containers for raising medaka outdoors.

There are various tubs available, but the 60-liter size is the most popular for raising containers. My family has dozens of 60-liter and 30-liter tubs set up outdoors for raising medaka. Additionally, blue, black, or green tubs can enhance the color of medaka.


Link to Styrofoam Container on Amazon

Styrofoam is an excellent container for raising medaka because of its insulation properties. It maintains a stable temperature, making it a comfortable environment for medaka, even if the temperature drops at night outdoors.

However, styrofoam is white, which can cause patterned medaka to lose color. In this case, you can buy black styrofoam or paint it black with spray paint to make it suitable for raising medaka. However, styrofoam degrades over time, often becoming brittle after a few years.

Transparent Storage Case

The transparent storage case is a clear container sold at Daiso. Although it’s only 7.7 liters, it’s enough for raising a pair of medaka.

These containers are popular for displaying medaka at shops and are widely used as raising containers. They cost only 300 yen, much cheaper than similar-sized plastic cases.

Link to Transparent Storage Case

NV Box

The NV box is a flat-shaped storage case that is durable enough for outdoor use. It comes in 13 liters and 22 liters, allowing you to use them for different purposes. They are also very cheap, costing a few hundred yen to less than a thousand yen, making them recommended containers.


Planters are also popular containers for raising medaka. They are quite large and designed for outdoor use, making them resistant to deterioration. They are used not only for raising medaka in biotopes but also by fish farmers.

Moreover, some say that natural materials used in planters positively affect medaka’s growth. However, planters require modifications to seal the holes, making them less suitable for beginners. For those who can make the modifications, planters are recommended raising containers.


Pots are a standard item for raising medaka outdoors. They are very stylish and make great interior decorations, often used as raising containers in biotopes. Plastic pots cost less than 1,000 yen, but branded pots can cost over 10,000 yen.


TROFAST is a container sold at IKEA. It costs around 400 yen and has a capacity of nearly 20 liters, making it very cost-effective. It also comes in dark colors like black, making it ideal for raising medaka. The downside is that it can be hard to obtain if you don’t have an IKEA nearby.

Stacking Box

The stacking box is a container sold at Seria that can be stacked on top of each other. This feature makes it ideal for raising medaka in limited spaces like indoors. However, it only has a capacity of about 4 liters, so it’s suitable only for breeding or egg storage. Moreover, production has ended due to rising plastic costs.

Recommended Medaka Raising Containers: Aquarium + Square Storage Box

The recommended containers for raising medaka are aquariums and square storage boxes. For indoor use, transparent containers like aquariums or plastic cases are best for easy observation.

On the other hand, if you are serious about raising medaka, using 30 to 60-liter tubs is recommended. They are sturdy and can hold many medaka, making them popular among breeders and enthusiasts.

For those not going to such lengths, the Daiso square storage box is highly recommended. At 15 liters and only 200 yen, it’s the most cost-effective raising container for medaka.



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