Aegle... looks like use sand. Not the greatest in my opinion. They love growing in soil that drains super fast. Mostly Perlite, and similar materials. With sand you need to ventilate  somehow or else the mold will eat you yote eventually. It happened to a friend that 'had' a large collection. He was not happy

Peyote coyote, looks like you are running cfl's in your setup. What is your rule you apply? 2 bulbs per square foot? How many watts, if you don't mind me asking.