watering cattleyas

[iamppdoc]

I am new to the forum and have been a "casual" orchid grower for years. Now retired, I would like to learn more about what I have been doing and decrease the rate at which I kill orchids. I have about 60 plants, mostly cattleyas or laelia cattleyas, with 6 or so phalaenopsis, and a smattering of other plants. They are housed in a two sided greenhouse facing south-west (The north and east sides are the house walls and door). There is a mist spray system, kept at about 40%. Temperature is about 80* in the day and 60* at night. The cattleyas are planted in course bark mixture and most pots are clay. I have never understood how often to water. The planting mixture, to me, always seems dry and my instinct is to water every day, yet I read "water once a week". Is there an ideal routine? How often to fertilize? I know this is a hugh topic, with no "one size fits all" answer, but I would appreciate some thoughts.
Thanks, Ed