What is Hydroponic Gardening ?
http://en.wikipedia.org/wiki/Hydroponics

and

http://www.hydroponicmicrofarms.com/

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Stealth Hydroponics DWC Basic Kit

Hydroponic Food Production: A Definitive Guidebook for the Advanced Home Gardener and the Commercial Hydroponic Grower, Seventh Edition

Hydroton Leca Clay Orchid/Hydroponic Grow Media – 2 lbs.

Hydroponic Handbook: How Hydroponic Growing Systems Work