Growing medium for small Catts

[Jeffery]

I was wondering about the growing medium I choose to use for my young Cattleya's, of course after trimming back unhealthy roots, there was not a lot of root left, I choose chips only because of the fact that Catts need dry out between waterings, my question is, it appears the chips may be a bit large for these small plants and there roots and the plant is not holding firm in the growing medium, there like a very lose tooth ready to pop out, any suggestions?
Also in that other pic is some new growth on one of my Catts, the roots look awful in the very close up pic, but when I trimmed I left only firm/fleshy root, are they maybe just staind from the chips or something?