Every plant has to be watered, whether desert or tropical in nature. In my experience, 90% of orchids are killed by over-watering, not under-watering. Perhaps you fall in that other 10% where the plants die for other reasons than "drowning".
I am sure this will be redundant since I have previously posted similar statements, but be sure your orchid plants are not growing in sphagnum moss and that the pot is well-draining. Those are two things that first come to mind since they are usually the way the commercial grower packages their plants - in sphagnum moss and often without adequate (if any) drainage. Most orchids are epiphytic, and your "Moth Orchids" certainly are, so though those roots must have adequate moisture/nutrients, they also must have access to air to thrive.
There are folks that say they grow their orchids in sphagnum moss and are successful in doing so. My hat is off to them. I believe the secret to their success is that they do have their orchid(s) in a well-draining pot and that they water less frequently. But the real secret is that when they water they sit their plant(s) in a basin of water for a few minutes so that the sphagnum moss can re-hydrate. If you water dried-out sphagnum briefly, the water simply runs through the moss but really doesn't saturate much of it. Therefore, the moss stays dry and the plant will wither and finally die.
