Hey everybody, I finally finished my first window farm (WF). It consists of an air lift and 2 rows of plant containers, with 5 containers in each row.

I put together a DIY guide, see it here (pdf).
I also made a Danish version of the guide (pdf), which includes prices and where to get the parts in Denmark.

I started figuring out how to build a WF, from scratch, about 3 months ago. I live in Denmark so buying a kit was out of the question. It took me a while to understand how the system was supposed to work, and then another while to figure out how I was going to build one myself. I had no experience working with the stuff needed to do this. Stuff like air pumps, tubes, and valves so it was all very confusing to begin with. I didn’t know anything about growing hydroponically either but ever since I saw the TED talk with Britta Riley, about a year ago, I have been interested in the project.

Now my WF is finally up and running and the plants grow bigger every day. So I want to thank this lovely community and the people behind the WF project for teaching me. It has been a lot of fun, and a little infuriating from time to time, when something just wouldn’t work the way I wanted it to.

I went through a couple of test systems, all of the air lift type, before landing on the one I am using now. At first I tried anchoring a tube on the bottom of a big water reservoir, but even though I knew this worked for others, I never managed to make it stable. The air from the pump kept flowing back into the reservoir, instead of lifting the water upwards. I then tried putting a small reservoir at the end of the row of plant containers. This worked very well; the reservoir had a tube in the bottom that went into a U-bend, which prevented air back flow to the reservoir. Unfortunately this setup forced me to reduce the number of plant containers I could have in a row, and I had to add water to the reservoir often, which was annoying. My current setup looks like this:

I put the reservoir, the air pump, and the U-bend below a shelf at my windowsill. There is a small gap between the shelf and the windowsill, where the tubes can get from below to above the shelf.

For reservoir I am using a 10 l (2.6 gallons) water container with a tap that is big enough for 2 tubes to fit into it. I made a plug of silicone sealant around the ends of the 2 tubes, to make a water tight fit (see info. box 1 on the sketch). To make sure the plug stays in place I wrapped some duct tape around the joint.

After leaving the tap of the water container each of the 2 tubes goes into a U-bend. *The U-bend needs to be at least 30 cm (12 inches) from top to bottom to prevent air back flow. (Thank you, Brian White, for sharing this information, the diagram you made really helped me a lot: http://our.windowfarms.org/files/2012/04/contest-with-u-April-7th.jpg)

After the U-bend there is a t-joint, where the water meets the air from the pump. I put a check valve on each of the 2 tubes leading the air to the t-joint, to prevent water reaching the pump (see info. Box 2 on the sketch).

In an effort to decrease the amount of plastic in my WF, and because I thought it would look good, I tried using coconut shells as plant containers. I hollowed out 10 coconut shells, cleaned them, and coated them on the inside with mineral oil to prevent them from absorbing water. I made a braided rope and nets for them to hang in. It looked really good but unfortunately the shells cracked. I think it happened because the shells I got were very old and dried out. I bought them all the same place but later on I tried with a shell bought at another place and it did not react the same way as the others. So I still think it could work with coconut shells, but I grew too impatient and my seedlings grew too big for me to do it all again with other coconuts. I turned to the well known plastic bottle instead, and I am very satisfied with the result.

I reused the rope I used to hang the coconut shells from but had to find another way to attach the new plant containers to the rope. I ended up with a kind of button on system which allows each plant container to be removed without dismantling the entire row. This highly modular system has the advantage that I don’t need net pots in the containers. I couldn’t find any net pots that would fit so I had to do without. If I do get my hands on some good net pots I will use them, though.

So I wanted to use coconut shells as plant containers, partly, because I wanted to reduce materials that could leak toxins into the water and plants. About this I have now come to think that the plant containers are actually the least important part. Most of the time, the water is in the reservoir or the tubes, so it’s more important that these parts don’t contain anything that will leak into the water. As the water drips into a plant container it goes straight through the clay pebbles and into another tube. Most of the clay pebbles that come into contact with the container are dry, as the water runs through the center part. I therefore don’t think the plastic bottles will be able to leak anything into the water, and if it does it will be minimal, compared to the reservoir and tubes.

These are the things I used to make my WF:

1    Air pump: Sera air 275 R plus. It has 2 outlets, a power regulator, and it comes with 2 check  valves

2    Water container with tap: 10 l (2.6 gallons). (It has the glass and fork symbol, which     means it’s intended for food contact; http://en.wikipedia.org/wiki/Food_safe_symbol)

3    Tube: 4/6 mm (0.15 inches/0.23 inches). I used about 6 m in total (19.6 feet)

4    Tube close up: It has the glass and fork symbol too.

5    T-joint and check valve: I used 2 of each.

6    Water bottle: 2 l (0.5 gallons). I used 10 of these.

7    Twine: 2 mm. (0.08 inches). I used about 10 m in total (32.8 feet).

8    Hooks: I used 7 in total (2 for each row, 2 for the water container, and 1 for the pump)

9    Spray paint: 1 can

10  Buttons: About 1 cm in diameter (0.4 inches). I used 40 of these.

11   Wire: 0.3 mm (0.01 inches). I used about 2 m in total (6.5 feet).

12  Power drill

13  Drill bit (4 mm – 0.15 inches) and screw bit (6 mm – 0.23 inches).

14  Hobby knife

15  Scissors

16  Belt punch

17  Duct tape

18  Silicone sealant

19  Clay pebbles (Leca): I used about 5 l in total (1.3 gallons).

20  Nutrients: Biosevia grow and Biosevia bloom

21  PH test kit (I didn’t use this to make the WF but it’s good to have afterwards)

22  Seeds, soil, egg shells, and egg tray.

23  Planted seeds in egg shells. This is how I grew my seedlings.

The essentials for making an air lift type WF: air pump, water container, tubes, valves and t-joints, grow medium, and nutrients.
The rest (tools, plant containers, plants) can be improvised.

After making the plant containers and assembling the system I transplanted the seedlings into the WF by carefully uprooting them, cleaning the soil from the roots, and putting them into the clay pebbles. The seedlings I have transplanted have all survived, it’s been about 2 weeks now. I also tried transplanting some cuttings from grown plants into the WF. One cutting was from a tomato plant and the others were from a basil plant. The tomato plant cutting had been growing in soil for a while and had become rather large. I thought it had grown too big to survive the transplantation and for a couple of hours it looked like it would die. Then it suddenly started getting better and the next day it was definitely on the mend. After 2 days it was back to normal. (The bend on the stem is caused by the way it has been growing before being put in the WF).

1 hour after transplantation

The next day it looks better

2 days later it's back to normal

The basil cuttings (3 in total) had different reactions: the first had grown pretty big in soil but it had no problem adjusting to the new environment. The second had not developed roots yet and for a long time, after putting it in the WF, it looked like it was dead. All the leaves fell of but I just let it be and now it has developed new leaves and looks like it will survive. The third already looked rather droopy when I put it in the WF and like the second one it dropped its leaves and looked like it was dying, but now it has developed new leaves too.

Besides tomato and basil I am growing chives, thyme, chili, and lettuce.
Row 1, from the top: chili, basil, thyme, chives, and tomato.
Row 2, from the top: chili, basil, thyme, lettuce, and chili again.Later I want to grow more lettuce and some strawberries, cilantro, mint, and pepper.

I don’t have a timer on my system at the moment but I will probably invest in one later on.

Pdf guide (English)
Pdf guide (Danish)

Thanks for reading and happy window farming.
Maj

Hello, I’ve attempted my first window farm this week as a prototype for class. It’s been a bit difficult to find proper supplies in Hong Kong due to language barriers. Challenges and questions I’ve come across while exercising my poor engineering skills. I will be using black socks to cover the bottom of the bottles.

1. My seedlings have already been attacked twice with aphids and fungus gnats in it’s growing plugs. I had to start a fresh batch. If the seedlings are already so sensitive to the  moisture and humidity, how soon will my window farm be attacked by these pest? Anyone have experience with handling this in a humid country?

2. My tubing is too stiff to direct it away from the seedling. I’ve seen some systems using a toothpick or wooden chopstick, but my result was a moldy chopstick. I ended up using a fishing wire just to hold it down and a tape to keep the tube in place. I obviously need to find a better alternative. 

3. Reservoir problem. Due to the limited space in HK, I don’t have the luxury to have a big bottle for reservoir so I attempted to use a ketchup bottle on the bottom. I found the tip was a good way to plug the tubing in (I still need to reinforce it with plumbers tape, but haven’t found it yet).

4. Cutting through plastic was the biggest challenge.  I am not a very handy person, but I attempted to use the drill to make some holes on the bottom of the bottles but the bottom is thicker than the rest of the bottle, so I am not able to cut through it. In the end, I made a big circle but the bottles don’t fit perfectly. Any suggestions? I thought about using sticks to reinforce it.

5.I wanted to try out using water beads instead of clay pellets. Anyone have any success in it?

Hey guys,

I’m about to start building my first system having looked at the plans for all three versions. I have a few questions about modifications that immediately spring to mind as I’m setting up.

1) Why does the bottom reservoir cap assembly in version 3 need to be the way it is? It seems like version 2 system seems a lot more simple, is there any reason why this can’t be used in a version 3 set up?

2) Why could the hydroponic cages not be placed deeper down the bottles? That way more plants (and bottles) could be accommodated in a single column. You’d need to cut down the bottles to do, which would require a bit more modification to the system, but I don’t see why this would be too difficult.

I realize how green I am to all this, so feel free to tell me if my ideas wouldn’t work and why!

Thanks.

Hi everybody,

I’ve just about finished construction on a 2-column windowfarm, and I am just waiting for my seedlings to get big enough to put them in.  I’ll post some pictures when it’s up and running.  Anyway, I have some comments and reflections on the “official” instructions and parts list.

So, I followed the instructions pretty closely except for on two points: first, my windowfarm is suspended from a free-standing frame on casters (which doesn’t really affect anything), and I used a t-joint for the airlift system.  The t-joint (a.k.a. t-valve) design is really simple and easy to install and use, whereas I found the method(s) outlined in the instructions to be really complicated and, frankly, intimidating.  The fact that the size of the check valve included with the air pump determines some of the other parts is pretty inconvenient.  Anyway, I hope the instructions are changed soon to include this more user-friendly design.

Speaking of the t-joint design, there are some issues that I ran into with parts.  Mainly, I bought a t-joint off the Petco shelf with all three openings the same small diameter.  It’s made for three of the standard 1/4″ OD tubes that come with the air pump.  The problem is that this makes a bottleneck for the flow of water.  At least I think it’s a problem.  Brian White say’s that the airlift tube should have an ID of 1/4″ for optimal performance, and he seems to have done his research.  I ran the 1/4″ OD aquarium tubing from the reservoir bottle to the t-joint, and from the t-joint up to the bottom of the 3/8” OD 1/4” ID rigid tubing from the parts list (McMaster.com #9245K17).  It works, but maybe it would be better if I had bought a wider t-joint and used wider tubing.

Speaking of things that could work better, there’s the Petco pump (#9902).  It’s not adjustable, as far as I can tell.  I guess I can add a little adjustable valve in the airline, but if I throttle it that way I’ll be wasting energy.  I think an adjustable pump should be recommended.

Then there’s the tubing.   Two kinds of tubing on the parts list reference McMaster part numbers, but the 3/8” ID flexible vinyl tubing for some reason does not.  Now, McMaster has a ridiculously extensive selection of tubing, so we should be able to find one that works.  I used #5103K36 (Chemical-resistant Clear Tygon Tubing, 3/8″ Id, 1/2″ Od, 1/16″ Wall Thk).  It was okay for joining the two long pieces of rigid tubing, but it was not flexible enough for the top, to curve down into the top bottle.  Technically speaking, the “bend radius” is too big.  Maybe #5231K185 (Clear PVC Tubing Chemical, 3/8″ ID, 1/2″ OD, 1/16″ Wall Thickness) would be better.

Chains.  I think the ball/bead chain is a good way to go, and McMaster was a convenient way to order it.  Weirdly, though, the part number on the parts list (#3606T16) turns out to be stainless steel chain, whereas in the instructions photos it looks like they’re using plastic.  It’s not important, but what’s up with that?  I also ordered the specified couplings (#3606T41).  They are listed in the McMaster catalog as being the same size as the chain, but for some reason the chain does not fit through the center hole.  I had to widen the hole.  I’m not sure what to suggest here.

I think that’s everything.  I don’t mean to complain; I think the design is great and I really appreciate having access to it, but I want to help make it better and easier for windowfarmers who come after me.  I hope this post is the right way to give this feedback.  Sorry it’s so long and boring!

Sincerely,

Bill

Here is my modification to the bottle caps @karenwslp made. After several leaks, and a need to just pull the tubing free during reservoir cleaning, I came up with an improvement to the bottle caps. Oh and these caps are from Poland Spring sports watter bottles. Just in case you can’t read the steps:
Step1) remove the blue cap.
Step2) Remove the plastic “Y” piece.
Step3) Insert 1/4 inch coupler onto top part of cap (hexagon shape in cap)
Step4) Insert size “00″ flat washer inside cap. *note use pliers to push it in
*use a little bit of aquarium silicone on the coupler before inserting it into the bottle cap to add extra sealant!

I have only done this outside but it probably works good inside too. The advantages are, no pump, can use dirty water, very low tech, can work for a long time unattended.
Best vid for understanding it is http://www.youtube.com/watch?feature=player_embedded&v=3yQOVUR1TpQ

Playlist is at http://www.youtube.com/playlist?list=PLkzXlmAwZTZdjGtjJpCYm2gSGVGwA033M&feature=view_all
Brian

What’s the cheapest air pump and where can you buy it? Because I don’t really plan on spending $800 on a huge air pump…

Alice

This isn’t our first hydro build, by far, but it is our first one to be hung in a window! It’s in an east facing window in our living room & we love how it brings the same esthetic as a houseplant, but the benefits of FOOD!

This was about a week after we set it up. We started the beans & cucumbers from seed in a little greenhouse on top of the fridge. The top two pots are cucumbers and the bottom has 4 green beans.

We hung the pots with some hemp we had in our craft surplus & made the trellis out of the hemp & bamboo stakes. I’ve even made a bow and arrow out of the bamboo!

This is how the middle & bottom pot get watered. There is a piece of bamboo shoved up there to keep the tubing straight.

Here’s the reservoir, made from a cereal tupperware we got at Target & some ducting tape to make it lightproof. We took the little hinged pour spout off of the lid and ran the watering and drainage tubing through the opening. You can also see the timer there, right now we run the water pump for 15 mins every 2 hours from 6am to 6pm. As the plants get bigger we might have to adjust the schedule, but for now it works out.

We use a water pump we had around the house and it works great until the water level in the res gets down to about 25%. It’s a good reminder that it’s time for a refill without having the pump run dry.

Our first sight of beans!

Beans, beans….

….and more BEANS!!

Okay, enough beans. Here’s our first cucumber flower!

We’re getting a lot of male flowers, just waiting for that female! Well, that’s what we have so far. If you have any specific questions on what we used or how we use it leave a comment or send a message & we’d love to share!

Happy Growing!

-The Sanders

Hallo zusammen!

Note to english speakers: I’m writing this in German as its very localized information (translations and distributors).

Ich hatte auch mit guten Englischkenntnissen Probleme, die Begriffe auf der Parts List nachzuvollziehen, und in Deutschland ausfindig zu machen. Damit andere von meiner Recherche profitieren können, schreibe ich mal eine ungefähre Einkaufsliste zusammen. Das Setup kostet ca. 100EUR, die benutzten Plastikflaschen geben da leicht einen falschen Eindruck. Falls einem das zu teuer ist, erstmal auf die Pumpe verzichten, einfach die Flaschen ohne Pumpe zusammenstecken und jeden Tag von Hand gießen/umfüllen. Alternativ und noch einfacher, der Self Watering Propeller Garden.

Die Werte beziehen sich auf eine v3 Windowfarm mit 5 Flaschen, mit T-Valve Airlift Technik (anstatt Ballnadel).

• 5x 1.5l Plastikflaschen (ca. 3EUR, Edeka/LIDL/ALDI o.ä.)
• 1x Trinkflasche mit Sport-Trinkverschluss (ca. 1EUR)
• 1x Dünger GHE Dünger Set Tri-Pack (20EUR, GKB Shop)
• 10l Substrat Blähton (8EUR, GKB Shop)
• 4x Netztopf 7/5 (0.30EUR Stück, GKB Shop)
• 1x Silikonkleber (7EUR, Zoo Royal) (für die Zuleitung aus dem Wasserbehälter) 
• 2m Aquarienschlauch 4/6mm (3EUR, Zoo Royal) (für Luft- und Zuleitung, nicht für Steigleitung)
• 1x Elite Sicherheitsventil (2EUR, Zoo Royal) (für Luftschlauch, auch “Rückschlagventil” genannt)
  Sicherheitsventile mit Feder sind nicht zuverlässig mit einer Luft+Wasser Kombination, ich bekomme trotz Ventil Wasser in den Luftschlauch. Einfach weglassen und Pumpe höher hängen (siehe mein Safety post) 
• 1x 1 Eheim Luftpumpe Air Pump 100 (22EUR, Zoo Royal) (leise und regulierbar, ein Anschluss)
• 1x Schlauchverbinder 4 mm T-Stück (3EUR, Conrad)
• 1x Schlauchverbinder 4mm l-Stück (3EUR, Conrad) (sinnvoll zum Kombinieren von Schlauchlängen)
• 3m LDPE Schlauch 6mm (1,50EUR, Conrad) (für Steigleitung, geringerer Wasserwiederstand)
• 1x Mini Tageszeitschaltuhr (3,50EUR, Conrad) (für Pumpe)
• 20m Angelschnur 0.3mm (ca. 5EUR, Ebay oder Baumarkt) (für Aufhängung)
  Alternativ: Krokodilklemme mit Schrauben, oder Seilklemme/Simplexklemme und 1-2mm Drahtseil  
• 1x PH Wasser Teststreifen (ca. 4EUR, Ebay)
• 1x Sprühlack (ca. 7EUR, Ebay oder Baumarkt)

• 1x Mini Tageszeitschaltuhr (3,50EUR, Conrad) (für Lampe)
• 1x Tageslicht Energiesparlampe E27 23W (8EUR, Conrad)
  Alternativ: 1x LED Grow Lampe (ca. 30EUR, Ebay oder GKB Shop)
• 1x Kabel und Fassung E27 (ca. 6EUR, Ebay)

I’m new to this and have yet to make my own windowfarm; born, bred and living in Reykjavik, Iceland.  The idea of using my time and resources to grow my own vegetables, greens and fruit is very exciting to me.

But after researching the articles here a little, there is one BIG thing bugging me about the whole thing.  Why use all those synthetic materials to grow food?  Why not try to design a system that uses natural materials like glass, wood etc. as much as possible?  Best would be to use only natural materials, of course!  Don’t know if that is practical though.

What are your suggestions and ideas on this issue?  I would love to get some feedback on the use of natural materials only.