What a wonderful forum! Thank you all so much, I appreciate the great advice and kindness. I'm feeling much more hopeful knowing how to help. I also noticed today I think her newest pseudobulb has thickened up a bit and the leaves on that side look really happy, maybe the long soaks and grow light time have been doing something?
I chose the pot because it was 1-2 inches wider than the root ball (seriously, that thing was massive!) and I thought it would give her space to grow so I wouldn't have to stress her again with another repot so soon. Welp that backfired, time for another rescue mission! (But this time, a well-informed one. ;)) I'll have to order a smaller clear container along with the new bark. I'm looking at repotme's oncidium and seedling' imperial orchid mix, I have a mini phal that would probably appreciate a repot into finer bark as well, she's been very thirsty too..
live and learn!
Follow up questions,
1)I'm tempted to add a little bit of sphagnum or coco coir to the bark mix, yay or nay? (I feel like pure sphagnum always molds for me, even after I started soaking in hydrogen peroxide prior to use. maybe it's a bad batch)
2)how exactly do you recommend watering? Every 3 days sounds good, but would that be running water over the roots for an amount of time or soaking? I always use distilled.
3)I feel so bad for disrupting those beautiful roots, I imagine a fair amount have dried up or broken and are now dead. Best to clip these with sterilized shears, right? (I heard if they squish/outer layer pulls off they're goners)
Once again, I so appreciate the wonderful expert support of this kind community. Thank you! <3