Miltoniopsis, however, need to be semi-shaded so the lovely foliage does not get scorched. Frequent during warmer, sunnier periods. Less frequently in Winter. NEver allow them to dry out for long.
Crinkled leaves are a sign of insufficient water.
Use overhead misters lightly to reduce leaf temperature in warm conditions. Monitor pseudobulbs carefully to prevent shrinkage. Regularly at strength. Do not use fertilizers containing urea on orchids, because urea requires breakdown by soil microbes that aren't generally in orchid media. Toxic salts can build up and damage roots.