Koi are deeply loved by aquarium enthusiasts because of their gorgeous colors and elegant postures. However, to raise koi well, it is necessary to comprehensively control many aspects such as the environment, water quality, feed, and daily management. The following are the detailed feeding methods:
I. Feeding Environment
Selection of Fish Tank/Fish Pond
Fish Tank: Suitable for small-scale feeding or indoor viewing. It is recommended that the length is ≥ 1.2 meters, the width is ≥ 0.5 meters, and the height is ≥ 0.6 meters (the water depth is about 0.4 - 0.5 meters) to ensure that the koi have enough swimming space.
Fish Pond: An outdoor fish pond is closer to the natural environment. It is recommended that the area is ≥ 3 square meters and the depth is ≥ 1 meter (anti-freezing measures are required in winter). Aquatic plants (such as water lilies) can be planted to purify the water quality.
Material: Glass tanks have high transparency, which is convenient for viewing; cement ponds need to be coated with waterproof paint to prevent alkalinity; canvas ponds are suitable for temporary or mobile scenarios.
Filtration System
Physical Filtration: Use sponges, brushes, etc. to intercept large-particle impurities.
Biochemical Filtration: Cultivate nitrifying bacteria to decompose ammonia nitrogen and nitrite (such as ceramic rings, bacterial houses).
Recommended Configuration: A bottom filtration system (suitable for large fish ponds) or an external filter (such as a drip tray, filter barrel), and the flow rate needs to be 5 - 10 times the volume of the water body per hour.
Oxygenation Equipment
Koi have a large oxygen consumption and need to turn on the air pump or fountain - type oxygenation for 24 hours to avoid floating head or death caused by lack of oxygen.
II. Water Quality Management
Water Quality Parameters
pH Value: 6.8 - 7.8 (weakly alkaline), which can be adjusted with coral bone or baking soda.
Ammonia Nitrogen/Nitrite: Must be 0, otherwise it will poison the fish.
Nitrate: ≤ 50mg/L, which can be controlled by changing water or being absorbed by aquatic plants.
Temperature: 10 - 30℃ (the best is 20 - 25℃). In winter, a heating rod (indoor) or heat - preservation measures (outdoor) are required.
Water Change Frequency
Small Tanks: Change 1/3 of the water every week, using new water that has been exposed to the sun and is of the same temperature.
Large Ponds: Change 1/5 of the water every month. Cooperating with the filtration system can reduce the amount of water changed.
Note: Avoid changing all the water in the tank to prevent excessive temperature difference or sudden change in water quality.
Disinfection and Chlorine Removal
New water needs to be exposed to the sun for 1 - 2 days or use a chlorine - removing agent (such as sodium thiosulfate) to remove chlorine. Regularly disinfect the fish tank with potassium permanganate (1ppm) or chlorine dioxide, but make sure the fish have been transferred.
III. Feed and Feeding
Feed Types
Main Food: Special koi feed (containing protein, vitamins, minerals), and choose the particle size according to the size of the fish.
Supplementary Food: Live bait (red worms, water fleas) needs to be disinfected before feeding; vegetables (spinach, pumpkin) can supplement fiber.
Avoid: Starchy foods such as bread and rice, which are easy to pollute the water quality.
Feeding Principles
Frequency: Feed 2 - 3 times a day, and it is advisable to finish eating within 5 minutes each time.
Quantity: Feed more in summer (fast - growing) and reduce the amount in winter (slow - metabolism).
Time: Avoid feeding when the temperature difference between morning and evening is large to prevent indigestion.
Seasonal Adjustments
Spring: Gradually increase the feeding amount to promote the recovery of physical strength.
Summer: Reduce feeding during high temperatures to prevent the remaining bait from rotting.
Autumn: During the fat -tening period, high - protein feed can be fed, but avoid overfeeding.
Winter: Stop feeding when the water temperature is < 10℃, and feed a small amount when the water temperature is > 15℃.
IV. Disease Prevention and Treatment
Common Diseases
White Spot Disease: Parasitized by Ichthyophthirius multifiliis, treat by raising the water temperature to 30℃ + salt bath (1‰).
Gill Rot Disease: Bacterial infection, use povidone - iodine or antibiotic bath.
Water Mold Disease: Fungal infection, keep the water quality clean and smear the affected area with methylene blue.
Enteritis: Overfeeding or feeding spoiled feed, stop feeding and feed allicin or norfloxacin.
Preventive Measures
Regularly change water and clean the filter cotton.
Quarantine and observe new fish for 1 - 2 weeks before putting them into the tank.
Avoid overfeeding and reduce the remaining bait.
V. Daily Management
Behavior Observation
Healthy koi swim actively and have bright colors. If there is floating head, separation from the group, or white spots on the body surface, it needs to be dealt with in time.
Cleaning and Maintenance
Clean the filter cotton every week and clean the filter materials (with the original tank water) every month.
Remove the algae on the tank wall to maintain transparency.
Considerations for Mixed Breeding
Avoid mixed breeding with aggressive fish (such as arowana), and can coexist with gentle varieties such as goldfish and grass carp.
VI. Advanced Techniques
Color Development Management
Feed color - enhancing feed (containing astaxanthin, spirulina), keep the water quality stable, and avoid frequent water changes causing color fading.
Body Shape Control
Proper feeding + sufficient exercise space can cultivate koi with a slender body shape.
Reproduction Preparation
When the water temperature rises to 20℃ in spring, raise the sexually mature koi (2 - 3 years old) separately and provide water plants or spawning boards.
Summary: The core of koi feeding is "stable water quality, reasonable feeding, and regular observation". Through simulating the natural environment and scientific management, koi can grow healthily and show their best state. Beginners are recommended to start with small and medium - sized varieties (such as Kohaku, Taisho Sanshoku) and gradually accumulate experience.