You guys don't want to see my mini phals.
They were my guinea pigs... Since I've never grown anything in straight sphag, I decided to repot them in fresh sphag with perlite and charcoal. Well... One is completely fine. Two of them are very sad.
I repotted them with more charcoal to see if they improve.
*note that I had trouble maintaining the balance. In sphag, I have troubles with both under-watering, and watering too soon.
At least I know I have to be careful with plants in sphag now!