Chris, as you probably know, I am a "newbie" when it comes to growing Adeniums. I have taken advice from several who have grown Adenium for years and grow a lot of them. Rick, KD, and Ursula are just a few who know so much more than I about growing these plants. This is just me, but I generally don't use sand. I know some growers use pumice, but again, I don't keep that so don't use it. If it were me, and I had some standard potting soil, I would make a mix of 1/2 potting soil, 1/4 cypress mulch (chunks), and 1/4 super coarse perlite. I would want a media that does retain some moisture yet is very well-draining.
Perhaps others, more experienced in growing Adenium, will chime in and give you better advice than I.
