Lately I have been experimenting with new indoor growing methods. One I am working on now is called Fogponics and is a variation of aeroponics (growing without soil). Fogponics uses a nebulized nutrient mist generated by ultrasonic foggers.
Ultrasonic foggers require an optimal depth for good fog output. You can buy floats for between $10 and $25 or even higher. This video covers my DIY solution to this problem. The depth of water over the fogger is about 1.5 inches or so.