This system can churn-out a salad per week, but it is definitely not the place to start if you are a beginner. This was our community’s first design and is a little more of a challenge. The window farm described in this How-To is a reservoir system. A water pump on a timer periodically pumps water and liquid nutrients from the bottom reservoir to the top reservoir. There are small holes drilled into the underside of the top reservoir. Small drip emitters with valves let out a constant drip of water and nutrients into a column of plants. Each plant sits in a grow medium in a net cup (a perforated plastic cup commonly used in hydroponics), within an inverted plastic water bottle. The cap of each water bottle has a hole in it so that the water and nutrients can drip from one bottle to the next, from the top to the bottom of the column of plants. The bottom-most bottles are connected to tubing that takes the water and nutrients into the bottom reservoir, where it sits until the pump turns on again.
Water pump systems are a little more finicky and are susceptible to clogging. Most of the community has moved toward the airlift design so unless you are very comfortable with tools and handy, we suggest trying the airlift how-to.
IMPORTANT ELECTRICAL SAFETY UPDATE!!! Please remember to include a drip loop on electrical components of this system. Make sure the cord hangs down below the outlet and then goes back up to plug in. Make sure you do not have an outlet directly under your reservoirs.
Download the PDF of the How To instruction guide here. Please note that we ask anyone who downloads the how-to to register on the site and to come back and post as you build, not just when you’re finished. You give back to the project by participating on the site. Bring questions, ideas, results of your testing various processes. This is a mass collaboration on the R&D of these systems.