There’s a huge array of hydro sites out there, here are a few of our favourites:
Instructables DIY Hydroponics: A great resource for DIYers.
Growell: UK’s biggest online retailer.
Taproot Hydroponics: Atlanta-based hydroponics and indoor gardening store.
Urban Turnip: Our sister site about container growing in small spaces.
Recirculating Farms Coalition: Eco-farm development.