Monnierara Millennium Magic 'Witchcraft' AM AOS seedlings leaves turning yellow

[Elli]

Hey. I live in Darwin, Northern Territory, Australia. The climate is tropical and it is the dry season, i.e. no rain, less humidity and cooler temperatures especially at night.
I deflasked some Monnierara Millenium Magic 'Wirchcraft' AM AOS two weeks ago. I was advised that there was some fungus in the flask, so I gave the seedlings a bath in Mancozeb. I have two pots with five seedlings each. They are in a noth western facing window with 60% shadecloth filtering the sunlight in the afternoon. This time of year it doesn't get too hot in this window, as the sun moves behind trees before fully shining on the window. I spray the pots with water twice a day.
The leaves on the seedling are turning yellow and look dry. As the flask wasn't cheap and I really want one of these beautiful Orchids I would hate for all of them to die!
Any ideas what I am doing wrong?
Thanks and have a wonderful day ☺