2. Potting Medium
I use a simple mixture of 3 parts of Orchiata bark, 1 part perlite and 1 part limestone chips. The principal growing medium is bark, the perlite is to improve aeration and drainage and the limestone chips serves for buffering any acid buildup.
For small plants, I use Orchiata 6-9mm with fine perlite, and for larger plants I use a 50:50 mixture of Orchiata 6-9mm and Orchiata 9-12mm bark and medium perlite.
Limestone chips are available commercially as Shellgrit, Calgrit and Selgrit. I prefer Selgrit which is produced by Omya in Bathurst NSW because the chips are uniform in size and does not have any fine bits.