Koi can be raised without oxygenation under certain conditions. When there is no oxygenation, koi can replenish oxygen through other means. For example, changing water frequently to keep the water quality clear, reducing the fish population density in the fish tank, feeding less to prevent the water quality from deteriorating, using a water circulation system to make the water flow, and planting aquatic plants in the water. These methods can effectively increase the oxygen content in the water.
In addition, maintaining a relatively low water level, adding a water pump to make the water flow, and promptly cleaning the water quality are also helpful in increasing the oxygen content in the water.
However, these methods cannot completely replace the oxygenation equipment. In cases where the density of fish in the tank is high or the water quality is poor, artificial oxygenation is still necessary. Supplementing the oxygen supply for a few hours every day can meet the needs of koi. Excessive oxygenation not only wastes resources but may also interfere with the growth of koi.
Therefore, although koi can be raised without oxygenation under certain conditions, in order to ensure the health and growth of koi, it is recommended to use oxygenation equipment as an aid.