What are the soil requirements for orchids?

Orchids are native to sparse forest valleys and grow in slightly acidic soils rich in humus. Family orchids must be cultivated according to this growth environment, with loose and ventilated, water and fertilizer conservation, PH 5.5 Mel 6.5 plant cultivation. There are many materials that can be used as plant materials, such as rotten leaf soil in the forest, coarse sand in the river, household cinder, as well as sawn wood, charcoal powder, plastic foam, decaying bark, broken bricks, grain husks, water moss, edible fungus waste, market immortal soil, perlite and so on. But each material has both advantages and disadvantages. For example, the rotten leaf soil collected from the mountain contains more humus, loose and breathable, water and fertilizer, and slightly acidic, which is very beneficial to the growth of orchid plants. However, it has fine particles, poor hydrophilicity, easy to solidify and lack oxygen, resulting in rotting roots, good coarse sand and cinder aggregate structure, strong air permeability and water repellency, but poor water and fertilizer conservation, and easy to dry and lose water.