AusBonsai

This has been used here to re-pot 400 trunks of all species this season .Water tested by a member of the local bonsai club and had no deterioration after 8 weeks in water .
That info was good enough for me to re-pot all my trees in a mix of this and aged pine bark .I did recycle the old mix and blend it with this "Kiwi Volcanic Clay" as i couldn't get Beveridge scoria anywhere .

Cheers Ian

I tried searching for kiwi volcanic clay to see what you have been using, Ian. This is what came up. No wonder your trees are beautiful!