Hi Thorsten,
This is difficult - aphyllus is considered similar to hard kultivierbar how pendulus or bufo, that has certainly different grounds in the species.
Before the images of the natural site here at aunt google, it is a harder mineral soil (clay?), but Hetterscheid has cultivated open bar in humosem substrate.
http://www.aroid.org/genera/serveimage.php?key=1115
In the bot garden in HH they stood in the Bromeliad, since it is assumed that the type requires very high temperatures; but as far as I know, the culture in HH life has failed.
In the Palmengarten in Frankfurt/a.M. There were at least two years ago some large plants; I don't know if that still live or in which substrate which are available.
I got 3 seeds last year, of which one has made a small tuber (0.5 cm) and pushes the just a leaf bud.
I'll probably put them in Seramis and keep slightly moist, and see what happens.
Last year it was noteworthy, the growth period was how just before the sheet was yellow and moved.
Good luck! It would be very helpful if you would tell your experiences...
Happy growing, Bernhard.