Koi like old water. There are microorganisms suitable for the growth of Koi in the old water, but there are no microorganisms in the new water, which is not conducive to the growth of Koi. If the old green water in the pond is used to breed Koi, it can improve the resistance of Koi and supplement trace elements to Koi, which can not be done by new water.
Every time you change the water, change one third of it. If it is a healthy koi, generally once a week to change the water can be, each time the water can not be all changed, can be appropriate to leave part of the old water in the fish tank, old water for two-thirds of the total amount of water can be. If it is sick koi, need to change water every other day, the purpose is to clean up the feces, shedding and so on, to avoid aggravating the disease of koi.
When changing water, do not fish out the fish, but directly pour out the water slowly, leaving two-thirds of the old water, and then slowly pour the water into the inner wall of the fish tank. If there is dirt inside the fish tank, you can use plastic pipes to suck the dirt clean by inverted siphon. Koi for the water can not directly use tap water, tap water should be placed in the sun drying, such as tap water will be discharged after the end of chlorine, and then change the water.
