Britta and I finished the first window farm prototype in her kitchen window in April. The system includes a pump in a bottom reservoir which is on a timer, to pump about 3 gallons of water/nutrient solution up to the top reservoir. The liquid then drips through the columns of water bottles that hold the plants.

We’ve listed each component below, and some of the lessons we learned.

The main components are:

• Reservoir 1 (a 5 gallon bucket on the floor)
• Water pump (orange)
• Reservoir 2 (a tupperware container on a shelf above the window)
• Large diameter tubing going up to fill Reservoir 2 (orange)
• Small tubing to and from each vertical component
• Clamps
• Water bottles
• Net cups with clay pellets
• Covering for roots
• Fishing Wire to suspend
• CFL bulbs and covers
• Light Timer
• Air Pump
• Second timer for pump

Scroll down for more details about each component. We have listed each component and ordering information on this site.

Reservoir 1 is a 5 gallon bucket on the floor with water and nutrient solution

- 500+ gallon per hour pump of high quality which makes it quieter. You can go with a cheaper one if like this it will only turn on 3 times a day.

- There is a timer on the pump which turns on for 2 minutes every 8 hours. It fills Reservoir 2.

- Along with the pump, the reservoir also has an aquarium air bubbler in it to keep the water aerated or moving so it does not stagnate. This thing is a problem because it is loud. We should find quieter ones because it stays on all the time.

Parts in this area:

• 5 gallon bucket
• Water pump (500 gph)
• Timer for pump with at least 3 on/off settings per day
• Aquarium air bubbler and airline tubing
• Tubing that fits water pump fitting (to go to reservoir 2)
• Extension cord
• Nutrient solution mixed with water

Reservoir 2 above the window

- The reservoir is filled via the tube coming up from the pump in reservoir 1. The size of the tubing was determined by the fitting on the pump.

- The reservoir itself is a tupperware container we got at the hardware store. In the future we would look for something made out of thicker plastic so it is easier to put the plumbing connections into. This plastic was thin and difficult to drill clean holes into. Also, technically this should be an opaque container since nutrient solution should not be exposed to prolonged light, but we choose clear so we could see the nutrient level and color.

- We used brass pipe fittings to connect the tube to the reservoir. They included the barbed brass and yellow rubber you see on the right of this photo. You cannot see the other side of the fittings, where we used the female pipe fittings to tighten the connection on the inside of the reservoir.

- There are 5 tubes which come out of the reservoir.

- They are clamped down really hard so that the 3 gallons of water in the reservoir takes the whole 8 hours to drip through the system – so the plants are getting a constant drip.

- We’ve realized now that instead of clamping, the better solution would be to use much smaller tubing – probably 1/8th inch – to slow the water flow – instead of needing the clamp the tubes.

Parts in this area

• 5 gallon tupperware container with lid
• Shelf and brackets to mount container on above window
• Barbed connectors to connect reservoir to tubing to plants, rubber O-rings and aquarium sealer
• Clamps (although these might not be necessary if your tubing is much smaller than ours)

Water Bottles

- The five tubes from Reservoir 2 extend into the top water bottles.

- The water bottles are suspended by 15 lb fishing wire tied to simple hooks drilled into the top of the window.

- The plants are in net cups, in clay pellets, resting in the water bottles, which, because of the ‘eco-shape’, are the perfect size for the net cups.

- Some of bottles have their caps on, with some holes drilled in the caps for the water to drip through. Another design we experimented with here has plastic martini glasses duct-taped to the bottles which have had their tops cut off.

- The water drips down through each plant and then to this tubing at the bottom, which brings the water solution back to the bucket reservoir.

- 6 100 Watt CFLs from Home depot in normal sockets. This may be overkill. However, in general the closer you can get the lights to the plants the more growth you can generate.

- Light Timer with 5 sockets goes on once a day and turns off once a day

These are some of the things we would change in the next version:

• Find better plumbing components
• Ian suggested using a chin up bar to suspend everything from at the top of the window to not have to drill the hooks
• Gabriel points out that a cheaper alternative to a chin-up bar might be some threaded pipe from the hardware store. They sell metal pipe cut to length and threaded on the ends, which screws into plates that are screwed onto the window frame. So some holes in window frame, but only in two places vs. a series as with hooks. Very strong.
• Remove the reservoir at the top and experiment with the pump so the water can go directly to the plants
• Play with the lighting design so less light bleeds into the apartment and out the window
• Find more flexible tubing for the bottom so that there’s not that large tube going to the reservoir
• Use containers other than water bottles
• Find a way to use coconut coir so it doesn’t clog the system
• Look into using copper
• Pump- cheaper? Non-electro?
• Air pump- quieter? Non-electro?
• Tubing adapters- easier?
• Reservoir 2 attachments
• Root covers- elegant?
• Containers- alternatives, less labor
• Wiring- Less messy
• Clamps- cheaper
• Suspension- Less invasive, more stable
• Aeroponics?
• Microgreens setup?
• Lights- positioning? use less light by sensor switches? filtering less harsh on eyes inside? less light pollution outside?

Here are a couple of sketches of what I’m going to try to build.

I’ve picked a not-that-sunny window in my kitchen, and want to build a system for growing various herbs that my wife and I like to cook with – thyme, basil, oregano, marjoram, cilantro, parsley, etc. I think I’m going to try nasturtiums too. I want to avoid hanging things vertically, and am thinking of three angled tubes with holes cut in the top for plant cups. Inside the large tube will be two tubes – a 1/2″ feed tube with some kind of drip emitters attached at the top of each cup, cups will be in some kind of tiny funnel, at the bottom will be a second drain tube. Hopefully all that will fit in a 4×4 square or round tube. I’ll have some kind of lights on either side of the windowframe to supplement the low natural light.

Feel free to contact me if you have questions about the design. I’m researching both how to apply drip irrigation parts to a vertical system like this, and whether there are eco-friendly alternatives to PVC as a building material.

Really great class tonight. I feel very energized by the challenge you’ve put to all of us. I didn’t leave a photo because I changed my mind about what window to use after hearing about the elements involved. My thought for an initial foray is a kitchen herb garden. I had planned on using a window on the sunny side of the house, but since lights are part of the concept anyway I’m switching windows to the kitchen despite it’s northern facing. Here are the dimensions: inside width of windowframe = 35.5″, inside height of windowframe = 72″, ceiling 8″ above inside top, windowsill = 6.5″ deep, windowsill 21″ above floor.

I like the idea of using thick PVC (or some more eco alternative?) with cutouts for the plant containers. I have some experience with drip systems so I’m going to investigate that kind of tubing and connectors for my system (inside the PVC). I’m thinking of using multiple chinning bars for maximum strength so nothing has to be suspended. I’d rather sacrifice some light and have something massively strong if it can be done at reasonable cost. If possible I’d like the whole system to fit inside the windowframe, including the lower reservoir and pump if possible. And the window needs to be able to open.

I’ll get a sketch into the computer soon and send it. I look forward to the discussion online. Thanks again for doing this.

I’ve ordered my pump and decided to try working without tubing… I hope that I can use fishing line to let the water drip down to the plants (with ceramic pellets acting like beads on the line). There are some major questions about evaporation and water flow, but I’ll let you all know if it works! I’d also like to make a basic PVC hydroponic system that garuntees some level of success- so if anyone wants to build that together, I’m game. I started posting some things on http://windowfarm.tumblr.com/ and I’ve attached my drawing plans as well.

xCaroline