How to turn over the pot in Wei Zi bonsai?

Requirements for turning over the pot of Lagerstroemia indica bonsai: change the pot soil every 2-3 years, and mix 5 parts of loose mountain soil, 3 parts of pastoral soil and 2 parts of fine river sand to make culture soil. When changing pots, organic fertilizers such as bone meal and bean cake powder can be used as the base fertilizer, but the fertilizer should not be in direct contact with the root system, so as not to hurt the root system and affect plant growth.

Selection requirements of basin: choose purple sand pottery basin or glazed pottery basin.