I agree, a well-draining mix is the important aspect. For most of my tropical plants I use a mix of 1/3 potting mix, 1/3 'Black Kow', and 1/3 coarse perlite. IF the potting mix does not have slow-release fertilizer, I will add a handful of Osmocote 14-14-14 per 2-3 gallon of mix. If I have some old Douglas fir bark mixture, I will add a handful per gallon. The fir bark mix will open up the potting soil so that it won't be quite as dense. I find that none of the available potting mixes have enough perlite, thus the addition of the coarse perlite.
