Growing orchids in glass containers is a nice way to see the plant and the roots. You’ll always know if they are healthy. It also keeps up the humidity around the orchid.
If you have orchids that are young or do not get large you can plant them in large, tall glass containers.
I’ve switched all my orchids over to semi-hydro, I haven’t lost a single one since the switch. I’m using clay pellets, you can find them online by searching for ‘semi-hydro’. I’ve not noticed any difference between brands so go for the best price. Glass pellets or rocks will work just as well. Smoother ones work better than rough ones.
Keep a little water in the bottom of the container. How deep depends on how deep the roots are. I plant them so there’s a half inch of potting medium at the bottom, put the bottom of the orchid roots on that, fill in around the roots with the potting medium and water up to the bottom of the roots. If the roots grow into the water that’s okay. Keep the water level where ever it makes the plant happy, some like deeper water than others.
I find the orchids, especially Phalaenopsis, do not do well in tall glass containers. It is too humid in the tall containers. They do very well in shallow containers, like Pyrex bowls.
If you use a large enough container to hold the entire plant, remove the cover or it’ll be too humid.
About once a year, usually in the winter before they spike I take the plants to the sink, dump them out, wash the pellets and glass and if needed bump the plant up into a larger pot.
If you find you’re watering your plant too frequently it’s time to move it up to a larger pot. What is too frequent mostly depends on how often you are able to water the plant.