Hello guys.. I have got 3 orchids in my home; however, one of them has some disease. I don't know what it is and what should I do with it, so I hope that someone can help me with this problem...I will describe it as good as I can.. The orchid with disease is white and flowers have some black/brown dots on it. Problem appeared about week ago.. I thought that maybe I water it too much but it is not the case. What should I do??