Could you tell me what ingredients are in orchid mix?
There are several types of growing media that can be used with orchid plants—redwood or fir bark, sphagnum peat moss, rocks, cork, charcoal, sand, potting soil, etc. A basic mix for growing orchids consists of coarse perlite, fir bark, and sphagnum moss. You can also add charcoal but this is optional. Generally, the grade of bark is dependent on the type of orchid grown. For instance, phalaenopsis orchids are usually grown in coarse bark, cattleyas in medium bark, and young orchid plants are best grown in fine bark.
For more info on soilless potting mix, this article will help: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/soilless-growing-mediums.htm