Medaka Tank and Container Cleaning Frequency and Reset Methods | Proper Cleaning Steps to Preserve Water Quality

Medaka containers accumulate algae, detritus (organic sediment), and substrate dirt over time. Regular cleaning is essential for maintaining water quality, but overdoing it risks removing beneficial bacteria and actually degrading water quality. Balancing cleaning frequency and method is key to maintaining a healthy medaka environment. The basic approach is the same even for improved varieties like Yohkihi medaka and Miyuki medaka, and this article explains the correct cleaning methods for medaka containers from daily simple cleaning to full resets.

Daily Simple Cleaning: A Weekly Routine

Daily cleaning of medaka containers is done about once per week. The most basic task is "removing debris from the bottom." Using a dropper or pro-hose (siphon-type cleaner), siphon out waste and leftover food accumulated at the bottom. There is no need to remove all waste at once; rotating through about one-third of the total area each time is sufficient. Discard the water removed this way and add conditioned water or dechlorinated water. This is the most efficient cleaning method, which also serves as a water change. Algae adhering to container walls can be removed by gently rubbing with a melamine sponge or acrylic scrubber. However, for outdoor cultivation, there is no need to completely remove algae; moderate algae serves as supplemental food for medaka and contributes to water purification. If floating plants (such as water hyacinth) become overgrown, thin them out and maintain about two-thirds of the water surface exposed.

Bottom Substrate Cleaning Method and Precautions

When using bottom substrate, removing detritus accumulated within the sand is important. When a pro-hose (siphon cleaner designed for substrate cleaning) is gently agitated near the sand surface, dirt accumulated between sand grains rises up and is sucked out with the water. For gravel-type substrates (such as Oiso sand), insert the tip of the pro-hose into the gravel to siphon out dirt. For soil-type substrates, since particles break down easily, keep to gently brushing the surface and avoid inserting deeply. When using akadama (red ball clay), particles crumble into mud-like material within six months to a year, so regular replacement is necessary. An important precaution when cleaning substrate is not to thoroughly clean the entire area at once. Large numbers of bacteria that decompose ammonia live within the substrate, and complete cleaning causes a sharp decline in bacteria and water instability. It is safest to rotate through one-third of the total area per cleaning.