Phalaenopsis and Dendrobium Root Problems (squiggly roots)

[Birb]

Hi everyone I'm a beginner orchid hobbyist with 2 orchids under my care; my dendrobium nestor and a phalaenopsis.

I have had these orchids for nearly a year now but I've noticed something (seriously) wrong with their roots; particularly my phal.

My phal is potted with charcoal and bark in a plastic pot with holes in the bottom and is watered once a week. Though the medium does not usually dry through within 3-4 days of watering.
I currently only have access to charcoal and bark and will be repotting my phal with charcoal.
It just finished flowering and is now sporting new leaf growth.

My dendrobium is mounted on wood and is watered every day.

From what I've researched I can conclude that there's been a fungal infection on their roots but I'm still not entirely sure as I've never come across a case as bad as mine.

Any other insight on the deformity, coloration or aftercare is very much appreciated.
(I do have access to hydrogen peroxide and isopropyl alcohol)



The dendrobium's roots weren't as squiggly(?) as they were now when I got them. (if you know what I mean)
They have had problems with toxicity and root rot in the past so any insight on treatment and prevention is very much appreciated as well.



There are also rings on the dendrobium canes and a black spot on the phalaenopsis crown, any help is very much appreciated.

Did I screw up that bad?