Orchids drying too fast

[Master Jedi]

Hi. I have several species of orchids including cattleyas, dendrobiums, and phalaenopsis. They're potted in an 80/20% of bark and sphagnum. The humidity is between 60 and 70 rh.
The temp is about 75 to 85 during the day and mid 60s at night. The problem is a lot of them seem to dry out so fast. Even though they are dry, should I still wait to water them, watering once a week, or should I water them as soon as they become dry?!?
I try to keep the room They're in as humid as possible but I will admit the rest of the house is quite dry. So do I water or do I wait?!?
Thank you for any input.