I just got my first orchids; 2 Phalaenopsis. I live in upstate N.Y. so it's cold. I have them in my spa room where I can keep them warm and humid from the spa running. I have them set on top of stones in a plastic dish with water - not touching the roots. And in a small southern window.I also use a fan to keep the air moving. At night the temp. drops a good 10 degrees by not allowing the spa to run. { I use it during the day just to raise the room temp.} I noticed yesterday that I have one leaf that turned totally yellow and feels soft. Can anybody tell what I've done wrong and how I can stop this from happening? I have only watered it once since I've had it [ 9th day today. The medium fells damp.] Please help? Thank you, odabel