Maximum Yield

http://www.maximumyield.com

Organic Materials Review Institute 

http://www.omri.org

Hydroponic Merchants Association

http://hydromerchants.org

Humboldt Hydroponics, Inc.

www.humboldthydroponics.com

Innovative Growing Solutions
(I.G.S)

www.igshydro.com

The Growing Edge Magazine

www.growingedge.com

Practical Hydroponics & Greenhouses Magazine

www.hydroponics.com.au

The Indoor Gardener Magazine

www.indoorgardenermagazine.com

GPN-Greenhouse Product News

www.gpnmag.com

Greenhouse Business Magazine

www.greenhousebiz.com

OG- Organic Gardening Magazine

www.organicgardening.com