Why can't I buy solar crystal in Huaxiang?

This is a task reward. According to the game strategy of Huacheng, we can know that the solar crystal of Huacheng belongs to the task reward, which is obtained through daily tasks and activities. Daily work includes plant planting, flower picking and fish pond stocking. Event rewards will be introduced from time to time, such as festivals and anniversary celebrations. Flower City is a simulated commercial game for planting and cultivating flowers. Players will play the role of flower shop owners, cultivate flowers by constantly collecting new flower recipes, and make beautiful floral works with the collected flowers.