1. Before changing the sand carbon, completely cover the raw water pump with impervious materials such as plastic, which is the electrical components close to the sand tank and carbon tank, so as to prevent water from entering the pump and burning the pump.

2. When filling resin, the central pipe shall be sealed with raw tape to prevent sand carbon from entering the central pipe.

3. When cleaning sand carbon, it is necessary to wash before backwashing. Pay attention to observe the pressure gauge during backwashing. If the pressure exceeds 3kg during backwashing, it is necessary to immediately hit the positive washing.

4. The filling volume of sand carbon shall not exceed 70% of the total volume, so as to have backwash space.

5. Generally, the raw water pump should be started for cleaning, and the pressure of tap water is not enough to clean, unless the pressure of raw water is very high.