As most orchids come from (warm &) humid climates, is it a good idea to place pots over a layer of water (not touching the pot / roots) to evaporate? I saw this advised for some jewel orchids, like Anoectochilus roxburghii, but thought it would be practical for most. Is this true? (also for the simple Phals, for instance)

I have pots that allow for this, so it would be easy to establish.

And how about spraying: I do this every day (roots, leaves), but am not sure it is good for all types (I have about 25 different ones). I do include a low concentration of SuperThrive, is that OK?

Looking forward to your experience & advice