In Brooklyn NY apartment. grow on windowsill, fire escape, some on the roof in the summer. A Dendrobium goldschmidtianum just rebloomed Stefano Giovannini's Photos | Facebook
I can't water twice a day.
I use a mix of coco chips, lava rock sometimes bark or sphagnum. With some i use the stringy coco fibers in net pot sitting inside a pot. Dryes fast but keeps the humidity around the roots.