Assorted Orchid Question

[theflyingkitty]

I recently acquired a bunch of baby orchids and set up a grow light in my humid bedroom where, at the time, it was generally a little warmer than the downstairs of the house where the rest of the collection is. Have had these about a month now.

Some of my downstairs ones are thriving, though I did move 1-2 small plants up as they needed extra attention.

ANYWAYS, I monitor the moisture in the pots carefully so that're damp but not too wet and never go bone dry.

Ok, onto the real stuff.

Nun Orchid had a few little leaves toward the bottom yellow when I brought it home so was no concern. Now I have two of the larger bottom leaves starting to yellow. Otherwise it looks fine.

One paph is growing like a little weed and looks so happy. It's brother (one has a mottled colored leaf, the other just green) is growing but a bottom leaf is getting ready to go.

Everybody else in the tray is doing great. Just wandering if it's a new environment factor or if maybe I should move those two downstairs to the window instead.