Question on mix for Dendrobiums

[Matorchid]

Hello, got a question for everyone

I would like to know what the best mix is for Dendro Nobles and The kinginanum variety
If you could explain what you use and why.?
I use imperial dark mix from repotme, I got it cause i am gross overwaterer,but it still seems to dry out to fast. I want to make my own but not sure the proper ratios.
I have black lava rock, MG PEAT, perilite(tiny little balls,cant find chunk anywhere),, charcoal,and bark (fir, redwood)

Any advice on these matters are trully appreciated,

Tony'Matomo' "Matorchid" Briceno