Recently I've transferred all my Crypts, regardless of species, to soil-based pots. These are your plant garden plastic kinds that your flowers come with. Normally people either discard them upon arriving at home or save them for some future purpose. I used a few for one such task. I fill the pots with regular garden soil; I know any soil should work, provided there aren't any harmful chemicals in it. I then topped off with gravel or pebbles. Basically, like what Art and Justin did with some of theirs; put in pots then either place inside a tank covered to maintain humidity or outside in a pond. I do this without ferts or CO2 injection. Plants are growing very well
Paul