Complete guide to building a medaka biotope from scratch: containers, substrate, plant selection, layout tips, and maintenance.
Key Takeaways
Complete guide to building a medaka biotope from scratch: containers, substrate, plant selection, layout tips, and maintenance.
A medaka biotope is an appealing style that lets you enjoy keeping fish in a near-natural environment. With lush aquatic plants, medaka swimming freely, and the feel of a miniature ecosystem, simply placing one on a balcony or in the garden creates a soothing space in your daily life. This article walks you through building a medaka biotope from scratch.
Choosing a Container
Select your biotope container based on a balance of aesthetics and functionality.
Ceramic water lily pots are the most popular choice. Ceramic provides excellent insulation with gradual temperature changes, and they look elegant. Choose one with a diameter of at least 40 cm and a water volume of 20 liters or more. Darker colors help suppress water temperature rise and enhance medaka coloration.
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Plastic tubs (mixing tubs) offer easy access to large water volumes and are convenient for managing multiple varieties. A 40-80 liter container provides stable water quality and can support many fish. Their utilitarian appearance can be improved by building a wooden frame around them or lining the perimeter with bricks.
Styrofoam containers offer the best insulation, excelling at preventing summer overheating and winter freezing. While plain in appearance, they are the most practical medaka-keeping vessels. Purpose-built black styrofoam containers for medaka are also commercially available.
Choosing Substrate
Akadama (red clay) soil is the standard biotope substrate. Its porous structure promotes beneficial bacterial colonization, and it gently lowers pH toward slightly acidic conditions. Spread 2-3 cm of hard akadama soil. It is inexpensive and widely available.
Aqua soil designed for medaka is also available. It offers better water quality stabilization than akadama but costs more.
Arakida (rice paddy) soil is actual rice paddy soil, notable for naturally generating microorganisms like Daphnia. While it makes water cloudy, the abundance of plankton it produces serves as food for fry.
Selecting Plants
Biotope plants should include a balanced mix of three types: submerged plants that grow underwater, floating plants on the surface, and emergent plants at the water's edge.
Submerged plants: Anacharis (Egeria densa) is the most robust and fastest-growing option with excellent water purification. Hornwort floats without rooting and doubles as a medaka spawning medium. Cabomba has attractive feathery leaves but is somewhat more delicate.
Floating plants: Water Hyacinth (Hoteiaoi) is the biotope classic; medaka lay eggs on its roots. Its growth rate is extremely vigorous, requiring regular thinning. Floating plants also provide shade from summer sun. Salvinia and Amazon Frogbit are also popular.
Emergent plants: Mini Cyperus and Hydrocotyle planted at the water's edge add a natural feel. Water lilies become the centerpiece when they bloom.
Layout Tips
Biotope layout should aim for a "natural-looking arrangement."
Place plants toward the rear and sides of the container, keeping the center and front as open swimming space for the medaka. Adding 1-2 stones or pieces of driftwood as accents enhances the natural feel.
Creating height variation is also key. Placing emergent plants in back and submerged plants in front creates a sense of depth. Sinking small pots with aquatic plants into the container allows easy layout changes.
Setup and Maintenance
After setting up the biotope, fill with water and let it run without fish for 1-2 weeks. During this time, beneficial bacteria establish and water quality stabilizes. Use dechlorinated tap water or water that has been aged.
Routine maintenance involves weekly removal of floating debris and topping off evaporated water. Since biotopes maintain water quality through plants and bacteria, avoid full water changes. When things look dirty, simply siphon out some debris from the bottom with a pipette.
Regularly thin out excess floating plants. Left unchecked, they completely cover the surface, blocking light from reaching the bottom. Keep about one-third to one-half of the water surface open.
Find Biotope-Worthy Medaka on BriChoku
Once your biotope is ready, it is time for the medaka. On BriChoku, you can purchase beautiful medaka varieties perfect for biotopes directly from breeders. For top-view enjoyment in a biotope, Miyuki-type medaka with luminous body glow and striking tricolor varieties are recommended. Tell the breeder about your setup, and they can select hardy individuals well-suited to outdoor biotope conditions.
