Actually I have 2 set up for emersed crypts. One outdoor, for easy sp and some anubias, and other one indoor for unussual sp.
We are having cold temperatures now, is winter of course. In the day ussualy it´s at 16ºC and 8ºC in the night, they are the extreme temperatures.
My cryptocorynes growing in outdoor set up are growing good. Only they have a low growth doe to the the low light in winter and the plastic sheet covering them (it´s a protection for the cold raining).
it look so
a top view
I keep warm into with a 50w aquarium heater under the gravel, and I distribute it with a little water pump around the set up.
Keeping a indoor set up is quite easy. An old tank, covered and lighting it lowly is enought.
Greets from Spain