Thank you to everyone for all your advise, and a great big "THANK YOU"
to Daisyl for trekking all the way out to my house to diagnose and show me how to better care for my orchids! Between the root trimming, new pot-ing, and re-locating (to a new window) I think they actually stand half a chance! Turns out the black-ish spots on the zygo were just from damage/stress, and they yellowing leaves were from the roots dying. Everyone has a new home now, so we'll see what happens!
