Is anyone experimenting with 100% mineral-based and/or inert substrates for lithophytic orchids such as limestone-dwelling Paphiopedilum spp? I realize that this idea conflicts with most advice and practice, but I like to think outside the box and experiment My understanding is that Paphs are typically grown in a mix with bark, etc, but I was thinking of trying a limestone-cliff species using only mineral elements (of which there are both acidic and alkaline options that could be mixed). Theoretically, as long as the pH matches that of the species natural preferences, the nutrients are delivered via fertilizer, and the substrate is flushed well, this could work, but I have no experience with this idea. My goal would be to significantly increase longevity and reduce repotting and root decay. Any info would be appreciated.