The newly bought fish passed the critical period of three days. During this period, the fish are fragile and need to adapt to the new water quality, and it is very easy to die during this period. Before the new fish enter the tank, it is necessary to raise the water. The fish tank should be disinfected and sterilized, and then a nitrification system should be established for the fish tank. After a period of oxygen explosion, new fish can enter the tank.

The newly bought fish has a critical period of three days, and the critical period for new fish to enter the tank is generally about three days. Fish are fragile and sensitive at this time and need to adapt to new water quality. It is extremely easy to die during this period.

Before new fish enter the tank, the water should be raised and the fish tank should be disinfected first. Fill the water tank with water, pour in potassium permanganate or chlorine dioxide, soak for a period of time, then change the water to clean the fish tank, and the fish tank will be sterilized.

As a small ecosystem, fish tank needs to establish a nitrification system to ensure the complete operation of the system. Add fish food and nitrifying bacteria to the fish tank, and then explode oxygen for a while. Then the new fish can be put into the tank.