I have H. minor growing in live sphagnum. I keep it in a large covered
aquarium standing in perhaps 1/4 inch of water. Light is provided by 4,
2-foot florescent bulbs (prob. should be more). Mine is regularly
producing new trap leaves, although they are typically about 1 1/2
inches tall rather than the 3 inches or so I would like to see. I
occasionally add water to the tank. I would be interested in hearing
about other successful long term approaches.
Tom in Fl