Sans really don't care, I actually used recycled mix for some of them, as long as it's fast draining.

I'd use the MG mix w/ added Perlite 50/50 each should be fine.

Sans aren't fussy abt mix, they can grow in almost anything as long as its fast draining.

Lena

Same here it is fine with the extra perlite. I make my mix a little different each time, but usually include some perlite, some commercial potting mix, a bit of good garden compost, coarse sand when I have it, maybe a pinch of bonemeal......eye of newt etc.