The roots of orchids are not like other plants. Their roots can be said to be very fragile. Even if they are properly maintained, it will take almost three months to fertilize. If it is too anxious to apply fertilizer, it will not absorb and burn the root system. And, after changing basin also can't carry on watering immediately, need a week time to be able to water and spray properly at least.
1. If the leaves on the outside of the basin are dry and black, that is, the roots are hurt when the basin is replaced. You can maintain them normally first. If there are no more adverse symptoms in a period of time, it means that the basin is replaced successfully.
2. If the bad performance is more serious, and the dried part is also expanding, it is necessary to take it out of the basin, check the root system, trim off the rotten part, and plant again after sterilization and disinfection.
After changing the basin, it's better to put it in the air circulation place. Don't be under the direct sunlight. Try to provide some astigmatism for it, or put it under the shade of the tree.