Quick Overview of the Kohaku Medaka
The Kohaku Medaka (Oryzias latipes var. “Kohaku”) is a highly sought-after, premium color strain of the classic Japanese Rice Fish. Reaching a maximum adult size of 1.5 inches (3.8 cm), this remarkable fish has been selectively bred over generations to mimic the iconic “Kohaku” pattern seen in prized pond Koi.
As shown in the image above, they display a translucent to opaque pearly-white body, boldly contrasted by distinct patches of vibrant red, orange, or amber along their back and head. Originally bred to be viewed from above in traditional ceramic bowls or patio ponds, their vivid colors also make them spectacular mid-to-top water schoolers in modern glass display aquariums. Exceptionally hardy and adaptable, they are a true joy to keep and breed.
Tank/Plant Profiles & Environmental Requirements
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Care Level: Very Easy / Beginner Friendly (Incredibly hardy)
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Growth Rate / Activity: Active, Peaceful Top-Water Schooler
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Lighting: Moderate to High (Bright lighting enhances their red and white pigmentation)
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Temperature: 16°C – 28°C (Highly adaptable; thrives indoors or in outdoor patio ponds)
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Tank Placement: Exclusive Upper Surface Layer Dwellers
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Minimum Tank Size: 10 Gallons (Must be kept in a group of 6+ minimum to encourage schooling and active surface behavior)
Local Care Tips for Bacolod Aquarists
Bacolod Tap Water, Adaptability & Outdoor Viability: The Kohaku Medaka is famous for its bulletproof hardiness. They thrive effortlessly in Bacolod’s typical neutral-to-slightly-hard tap water (pH 7.0–8.0) when properly conditioned with a high-grade dechlorinator. Because they originate from the rice paddies of Japan, they can handle a vast range of temperatures. In Bacolod, they are excellent candidates for outdoor balcony tubs or mini-ponds, where natural sunlight will rapidly intensify their brilliant red “Kohaku” patches! Indoors, gentle water flow from a sponge filter or baffled hang-on-back filter is preferred, as they are not strong swimmers against heavy currents.
Aquascaping Strategy & Floating Plant Synergy: Whether housed in an indoor aquarium or an outdoor tub, Medaka feel most secure with heavy top-cover. Provide a generous layer of floating plants like Salvinia, Red Root Floaters, or Water Hyacinth (for outdoor tubs). Females will use the trailing roots of these floaters to deposit their sticky clusters of eggs! Frame your underwater hardscape with hardy epiphytes like Anubias Nano, Java Ferns, or Bucephalandra bound to local driftwood or rocks—just ensure the creeping rhizomes of these epiphytes remain completely exposed above the soil to keep them from rotting!
Dietary Specifics & Nano Community Harmony: Kohaku Medaka have small, upward-facing mouths designed to feed at the surface. Offer high-quality crushed flakes, floating micro-pellets, and regular treats of freeze-dried daphnia or live baby brine shrimp. They are completely peaceful and 100% safe to house alongside adult Neocaridina/Caridina dwarf shrimp, Horned Nerite Snails, Pygmy Corydoras, and other gentle nano-fish. If kept indoors, a secure lid is recommended as they can jump if startled.
