Parrot fish is very sensitive to the change of water temperature, so it is necessary to grasp the time of changing water. When changing water, you can choose to change water around 10 o'clock in the morning when the weather is better, and usually changing water during this time has the least impact on them. Every time you change water, you can't change all the water, which will affect their normal growth. Therefore, every time you change water, you need to keep one third of the old water, and only need to replace two thirds of the new water.

Under the condition of manual curing, it is not necessary to change water every day, but every 4-7 days on average. If tap water is used when changing water, the tap water can be precipitated for 2-3 days and then the upper water can be used as new water. When changing water, you need to scoop up the fish and water together with a spoon. It is best not to use the net to catch fish, which can easily damage their skin. Pick them up with a spoon, and keep them alive.

Parrot fish usually don't need to put anything after changing water when the water condition is normal. However, if the nitrification system in the water tank is not good, some nitrifying bacteria can be put to improve the water quality.