Fungus, salt, or other? Also, two rot questions

[JKeys]

I've noticed some white stuff on a few of my plants. I have flushed the ones I noticed it on with rainwater, which reduced it on some but not all. My question is, is this salt, fungus, or something else?



Also, I have a healthy phalaenopsis that is currently spiking, and just recently put out a large new leaf. There are a lot of brown patches on the roots. Is this harmless, or rot?


Another rot question: I recently repotted some bulbos into sphag. They are both actively growing, but the roots look bad. Should I do anything now, or let it be?


Thanks a lot!