The best combinations of cleaning fish for koi are the scavenger fish, Chinese algae eaters, and corydoras catfish. These fish can not only effectively clean the environment of the fish tank but also are compatible with the living habits of koi.
Recommended Cleaning Fish and Their Characteristics
1. Scavenger Fish
- It feeds on algae, leftover food, and bottom dirt, which can significantly improve the water environment.
- It has a gentle temperament, and its color forms a visual hierarchy with that of the koi (the black and white stripes complement the colorful koi).
- Note: When the adult scavenger fish is relatively large in size, it may attach to the koi. It is recommended to observe it regularly.
2. Chinese Algae Eaters/Corydoras Catfish
- They specialize in cleaning the algae on the tank walls and the impurities at the bottom.
- Their flat body shape makes it easy for them to hide, and they will not interfere with the activities of the koi.
3. Loach
- It is adapted to living at the bottom and is good at cleaning up feces and residues.
- Its activity area is stratified from that of the koi, reducing spatial conflicts.
Other Optional Combinations
1. River Snail/Water Snail: They purify the water quality through filter feeding, but they reproduce relatively quickly, so the quantity needs to be controlled.
2. Chinese sucker: It is a gentle fish species and has a strong ability to deal with decaying food, but its body size needs to match that of the koi.
Precautions for Mixed Breeding
1. Body Size Control: It is recommended that the body size of the cleaning fish be less than one-third of that of the koi to avoid aggressive behavior.
2. Water Quality Requirements: Maintain a neutral to slightly hard water quality (pH 7.0-7.5), and the water temperature is preferably between 15-25°C.
3. Feeding Management: The cleaning fish need to be additionally supplemented with sinking feed to prevent them from attacking the mucus on the body surface of the koi due to insufficient food.