I have thought about it many a time and I will tell you why I don't.
The cost to cool/heat the room
The cost of running lights
The time it takes to change water and the waste of water. (I'm in CA...land of the drought)
Fear of mold
When I can overcome those hurdles I would like to try it.
I went to a sales demonstration and they have these really neat self contained trailers. Temp and lights are just right, water is recirculating/changed by a timer. Because they can control the temperature mold isn't an issue. Sounds great...for about 12,000.00 or more.