I need help with my orchids!

[Rorchid]

Hey everyone, I am new to this site and really excited to get some advice from people who have had personal experiences with orchids!
My mother has about 20 orchids, most are Phalaenopsis I believe, two are lady slipper orchids, and one is a peach fuzz, a couple I cannot identify.
Anyways I took over caring for them when i noticed there was white film all over the pots (salt buildup?) and their roots were growing out of the pots. I repotted all of them in a phal mix that includes bark, I have them in a sunroom with north, east, and west light exposure. They sit on the north west side of the room. I put a fan in the room for air circulation, a thermometer, and some sheer curtains to filter the sun.
When i repotted them they had root rot, I cut the bad roots out and I am hoping that they do well.
Should I put a humidifier in the room?
Any suggestions would be great and appreciated as I am completely new to all of this. I am going to continue to read. Thanks to everyone.
I will try to include pictures of them...