Send your gardening question to Dr. Smith by e-mail . I have a Dendrobium orchid which is potted with bark. The Dendrobium and many other orchids grow naturally on the bark of trees. That is why they are grown in the bark instead of soil.
Some people add lava rock to help increase drainage.
Potting soil is not recommended for this type of orchid, but I have seen people succeed with potting soil. It is much easier for root rot to develop in potting soils which do not drain as readily. You might want to find an orchid society in your area and benefit from advice from orchid growers familiar with your local conditions. A members of an orchid society should be able to look at your plant to determine which Dendrobium it is, and then give advice based on that. Regarding fertilizers, Miracle Grow is okay, as are many other houseplant fertilizers.