Do you spray for virus and bacteria? My vanda roots used to do that before I sprayed regular for rot. Now that I spray once a week I don't get this issue. After you treat it well, place it in a spot with a good breeze (often there is a corner of your home that gets more sunlight and wind than any other; that is the best spot). Your vanda will begin to put on new roots as soon as the infection is under control. I also use honey in my sprays for sick vanda to help give them a little added energy to kick what's ailing it.