The Trouble with Paphs for me is...
 

I use a mix specifically for Paphs. It appears to be fine fir bark, small charcoal chunks, perlight, and a small amount of chopped Sphagnum. I had another handful, or so chopped sphagnum, depending on pot size. Rotting sphagnum is generally not a problem since these get repotted quite often (like yearly.) Also you want to keep pot size pretty small - just large enough and deep enough for the roots.

I use coconut bark, alifor, charcol and that's pretty much it. They seem to like it.

Tin, I thought Paphs and Phrags were semi-terrestrial. The do live on the ground but in light fluffy leaf litter, not in dirt.

I use the following mix for standard sized plants:

4 parts fine fir bark
1 part coarse perlite
1 part small or medium charcoal
1 part peat
Dolomite lime for pH adjustment

For larger plants in 6" + pots, I use the same mix but with medium grade bark and medium charcoal, and I usually add a drainage layer of lava rock or styrofoam peanuts at the bottom.

Most Paphs are lithophytic, which means they grow on rocks in places where litter tends to accumulate. Sometimes this is hard to distinguish from terrestrial, since either way they appear to grow on the ground. Some Paphs are epiphytes.

The only practical difference is how moisture-retentive the media is. Paphs simply need to retain more moisture between waterings than typical epiphytic orchids.

Most Paph growers use a finer bark with amendments like chopped sphagnum, rock wool or peat. Many growers are using coconut chunks instead of bark, but care must be taken to ensure that all salts are properly leeched out prior to its use. Perlite is usually used, most often a finer grade.

The Orchid Zone uses lava rock mixed with fine bark. This sort of mix works well for heavy watering in a greenhouse, but I find it tends to dry too quickly in the home or outdoors.

Regards,
Rick

I use 50/50 mix of peatmoss & perlite, potted in clay. It works real well and I can pick this stuff pretty much anywhere.

I am starting to convert all of my paphs (and lots of my other orchids too) to semi-hydro. I can water freely and the roots still get plenty of air.