dracula failures - HELP??

[charley]

Well, that will teach me to look a little harder next time. Just found this "alliance." Sorry I am new here. I posted this to "Beginners" earlier today. Hi - this is my first post, be gentle. I have killed three Draculas so far. Two were D. lotax and I have lost the tag for the third one, but i think the species name began with a "b." These were all purchased mail order from two suppliers (reputable) and looked great for a while, though never got flowers. I am new to all orchids; I do fine with most standard Dendro's and Pluero's etc... For the Draculas, I tried one in a tropical terrerium, very wet and warm - rotted fast, turned black, dead.
Then I tried one in a damp but cool terrerium home, with a base of rock and sphagnum, in a pot with sphagnum kept damp - turned a little brown at base, turned darker, leaf ends turned brown, mold formed at base, dead.
Then I tried one in the same cooler terrerium but with top more open to keep it drier, but also in sphagnum moss - dead.
I have one D. lotax left in the cool terrerium with top slightly open in a pot with standard orchid bark mix. This one seems to be doing fair, but definately not thriving. I feed about once a month with light mix of commercial orchid food, like Miracid or the other big one. I keep the orchid mix damp. What am I doing wrong? Does anyone know of a good site for Dracula purchases and info?