When I first saw this website, I thought it was great on so many levels. My group of friends store food ,and growing some indoors year-round fits in with that concept of thinking about the future ,when the country may suffer food shortages. As a 6th grade teacher, I am going to have the students build a class windowfarm of their own.It will be fun to see how they troubleshoot! My setup  is not an airlift system. I am experimenting with a reservoir on top that drips down 3 containers to a receptacle at the bottom. I’m using a perlite/vermiculite  mix without net cups that I prime with water first. The drip is very slow and I hope it will stay wet enough until I get home from school to recycle the reservoir. I won’t have plants in the farm until I get the drip speed down. I want to thank the person who suggested using a 5 gal. reservoir on a single outlet pump. I have a double outlet pump for my next windowfarm which is an airlift. I couldn’t find needles, so I used a ” T’ connector with a single outlet and regular airline for the airlift tube. The middle of the “T” is connected to the check valve and air supply, the other ends are connected to the airlift tube. The “T” comes in where the needles would have been. I’ve been able to get 5 feet of lift with this “make-do-with-what-ya-got” setup. Thanks to everyone for  all the great ideas and comments and to Britta and company for the movement.

Finally sufficiently done with our aquaponic windowfarm to post a youtube tour of our set-up:

http://www.youtube.com/watch?v=8zq7T6QNrc4

It’s taken a bit of investment to get to this point, but I think I could pull one of these together for $40 (a bit more because of the fish aspect), and last weekend we gave one of these as a birthday gift to one of my pre-teen’s friends.

I’ve got two kids with good windows for this, so will post another video when I get the second windowfarm up and running.

Innovations:

1. Used an alternative method to perform the airlift, based on a post I saw here – my lift uses the ball inflation needles to inject water into the air hose instead of the other way around.
2. I use the “silencer” at the top of the drip line to support the weight of the assembly. It serves a decorative purpose (finial) and makes it crazy easy to support the whole assembly from a single near-vertical nail in the window casing. I don’t need to use any other supports given the exact 1″ hole I was able to drill into the bottom of each bottle.
3. I used double-sided velcro strips to fasten the tubing going up.
4. I used a 1/4″ OD tubing (short length, angle cut on exit) to control the drip. Don’t actually know if that’s a great idea, but I didn’t want the water splashing the windows and some plants supposedly don’t like getting watered “directly.”
5. I just use 1/4″ OD tubing from the lowest bottle to guide the return water back to the fish tank.
6. I use one of the variable control air splitters to ensure both the air lift and the air stone get enough air pressure.
7. I used a hole punch to round the corners of each “grow hole,” of which I cut 2 in each bottle. The “square” holes allowed me to get a jig into the bottles for a nice drilling support, so getting the 1″ holes drilled in the bottom of the bottles was a breeze.

We’ll see in a few weeks whether some of these “innovations” were really dumb ideas…

This is a summary of our build and experience so far.

Our window frame measures 75” x 31” so we thought two columns with five rows (ten containers total) would work well. We decided to use the recommended 1.5 liter water bottles for the containers, but instead of cutting one outlet per bottle, we decided to cut two on opposite sides and have two plants in each container. Each column is attached to a single wire cable that hangs from its own plant hook, loops through the bottom container, and back up. Wood dowels are inserted through each bottle (except bottom bottle) and alligator clamps hot glued to the wood dowels attach to the wire cable. Duct tape covers the bottom of the bottles to prevent the roots from drying out and minimize algae and mold growth. Rather than filling the net pots with clay pellets and then inserting the pot into the bottle, we eliminated the net cups, filled each bottle with the clay pellets, and the plants go directly into the bottles.

After reading about other farms, we first decided to go with the upper and lower reservoir system utilizing a water pump. After getting our supplies, the next step was to set up the watering system. We soon realized that to pump water over six feet vertically was going to require a heavy duty and more expensive water pump. We returned to Home Depot to purchase a fountain pump capable of 400GPH at 1’ lift, with a maximum lift of 7.3’ at $40.00. We then realized that due to the size of the pump, it would have to sit outside of our bottom reservoir, meaning we were going to have to consider the sealing aspect of our system to prevent water leakage. Our other thoughts about the water pump were the noise of the pump, the power usage, and fear of running the pump dry, which would mean we would have to go to a clear bottom reservoir to know when the water level was getting low to shut the pump off. With all of this adding up, we decided to ditch the water pump system, and move to the air pump system.

We purchased a Top Fin Air Pump 4000 with two adjustable airflow outlets for use with up to 80 gallon aquariums. Without looking at any diagrams or suggestions for the air lift system, we started experimenting with different ways to get the system to work. After days and days of different setups, numerous trips to Home Depot and PetSmart purchasing and returning products, and frustration beyond belief, we finally broke down and read other posts on the setup. After reviewing the recommended airlift setup and combining what we had already learned, and a bit by accident, we came up with a new airlift setup that works incredibly well and reduces gurgling. See our diagram below. As others have mentioned, the depth of the water is the greatest factor in achieving lift. Our bottom reservoir is a glass cylinder measuring only 4” diameter, however, the container stands 13.5” tall. When this is filled to 9.5” the max lift we recorded was 5’ 4”. When filled full at 13.25” we achieve an 8’ 3” lift, though 7’ 3” appears to be the optimal level for this water depth. Also as others have stated, keeping the air lift tube as straight as possible, especially into the reservoir helps achieve better lift.

What is excellent about the air lift system (once working) over the water pump system is the reduced cost of the setup, simplistic design and setup eliminating the top reservoir and having to seal and water proof the system, virtually noise free (no loud water pump), not having to worry about running the pump dry and damaging the unit, and the reduced operational cost (water pump consumes 80.5Watts versus air pump at 3.5Watts). Not only this, but the water pump system also suggests using an air pump in addition to the water pump to aerate the water so it does not become stagnant and reduces mold/algae from standing water in the bottom reservoir.

Our Plants

We decided to grow strawberries in 8 of the 10 containers, and peas in the other 2.  Using clay pellets with no soil, we purchased organic plant nutrient (liquid form) that says it is designed for soil and soilless gardens. We mixed the recommended amount of nutrients to water and filled our reservoir. During the day we would leave the air pump running and the water/nutrient solution would trickle down through our plants, and turn the pump off at night. Everyday we added about ¾ cups water due to plant use and evaporation. After about 4 days our mixture had become clearer indicating a higher water base than nutrient. Though our peas are fine, the strawberries after about the fourth day began to show a little black on the ends of the leaves, and after six days, some of the leaves were yellowing. What is interesting is that the strawberries closer to the top of the window farm show little to no signs of the discoloration. This indicates that the problem might be from a lack of nutrients to the lower strawberries.

We found out several things and are currently correcting those to see if it makes any changes. First, although the nutrient mixture said it was for soilless systems, this apparently refers to mulch, and not hydroponics. It also contained only nitrogen, phosphorus, and potash, but no calcium or other minerals which we read can contribute to our problem. We have now switched over to a dedicated hydroponic nutrient formula containing calcium. We have also been told that consistent watering and then drying out can be harmful to the plants. We purchased a timer that turns the pump on 15 minutes of every hour during light, and 15 minutes every two hours when dark. We also purchased a pH tester, although we might also purchase a tester for nitrogen, phosphorus, and potash.

Below is a table of our materials and costs.  This is an approximate estimate and you will see it is a bit more than the $30 mentioned on the window farm web site:)

This list only shows what we are currently using. It does not take into account extra tubing, needles, miscellaneous aquarium supplies, and the first nutrient solution, as these were items we tried but did not end up using. 

Structural and System Costs

Plant and Formula Costs

Total build cost = $165

Additional tools needed:

• Hot glue gun
• Drill with drill bits
• Exacto knife
• Scissors

Thanks for the fun adventure windowfarm.org

We will keep posting updates as our system grows!

I have just completed my windowfarm. A three step airlift system with the airlift tube inside the bottles. I was planing to do a four step system, but the pump could not pump up the water all the way.

The plants i have right now is (from above) habanero, cherry tomato and strawberry. I’m running the system with pure water the first day, going to add some nutrients tomorrow.

UPDATE:

The habanero and cherry tomato plants got an chock at transplantation. I think i should have let them get used to the bright light in the window before transplantation .

Some people have asked me about my system so i thought i would contribute with some more pictures.

The end of the tower is  inside the reservoir so there is no need for an extra tube between them.

The airlift tube runs up through the caps of the bottles. The holes in the caps is a bit bigger then the tube so water can pass through on the way down.

This is  the top section of my window farm. The airlift pumps the water up here and then the water follow the outside of the tube down through  each section and finally down to the reservoir again

The air pump used in my system is an regular aquarium air pump (Tetratec AP 100) that is used for 80 -150 L aquariums.

The nutrient solution that i use right now is  ”Blåkorn”. I have mixed about 5 grams of blåkorn with 2 liters of water, so far the plants seem to like it.

Alternate pump performance data

In the spirit of R&D, here is the performance data to my alternate pump design that  I had shown in my first post.  http://our.windowfarms.org/2010/03/10/just-getting-started-with-slightly-different-pump-design/  The design is easy to assemble and has been very reliable.

 The data shows the relationship between resevoir height, pumping height and flow rates.   I do not know how the air pump pressure effects these since I can not change that.  I think the general conclusions will hold true for any pump design including the standard 3 plant windowfarm design. 

As mentioned in the troubleshooting guide, http://our.windowfarms.org/2010/03/05/airlift-troubleshooting/ the resevoir level is very important.  Small changes in the level really effect your pumping rate and how high you can pump.  My one gallon resevoir level naturally drops about an inch a week.  As it drops the flow rate goes down, but it keeps working.   If I let it get near 5 inches, then the pump would stop working completely.

Ran across your site a while back and thought I would give it a try.  Spring is almost here and I am iching to do some gardening.  I made a free standing system since I have nothing to hang it from.  I had most of the parts laying around like the pump from the kids old fish tank.  They only things I bought so far has been the 3/8″ tubing and a 3/8″ tee.  I wanted to share the pump design since it worked pretty good.  The long 3/8″ tube goes in the top end of the tee.  A short piece goes in the bottom end with half cut off so water will get in when on the bottom of the tank.  A small piece of 3/8″ tube goes in the middle tee and then the 1/4″ tube from the air pump fits snug inside it.

I sprouted some seeds and put them in it, but they died.   I think they died since the leaves were too small and stayed wet all the time and I do not have any hydroponic solutions yet as well.  I enjoy the experimentation and will try again.

We are almost there on kits, Folks. We would love your input on a couple of things.

For more about why we are making kits, read this.

Here’s how kits are looking.

You will choose between a 2-column or 4-column windowfarm. You WILL have to be able to screw at least 4 screws into your upper window sill. The bottom bottle of each strand will be the reservoir.
We will probably produce the first batch by hand ourselves here in the Brooklyn shop but the next batches may be handled by an awesome little organization that hires the disabled just North of the city.

Get a sneak peek of the one we have in Brooklyn headquarters here.

Major points up for debate:
1) To give you the bottles or ask you to supply your own. If you supply your own, you need to drill through the tough end very precisely and this can be a dangerous task with a drill or a red hot cylinder. However, sourcing the bottles and getting them to you is very expensive on our end. What do you say? Would you be willing to pay a premium to not have to find, drill, cut, and paint your own bottles?

2) To include the pump or not. The petco pump is the best one we have found and it comes with air valves. However, some people have found that their pumps are duds. Having to deal with Petco’s duds will be a big burden on us that will take away from our mission work. We’d prefer to simply have a button while you are buying you kit that you press to order your pump from Petco separately. Is this a deal killer?

3) Lights. Almost everyone really needs them but no one ever wants to get lights. That is, until after they start raising their little baby plants and the plants come out looking leggy/scrawny. You can pump them full of nutrients but if they don’t have enough light to process the nutrients through photosynthesis, it is very sad =<. Anyway, I'm thinking we will sell lights as a separate kit. You would buy individual strands. Sound good?

Also, if you have a great business mind, experience with this kind of production setup, and some time to volunteer, we would love to hear from you. Send me a message by finding Britta under members.

So, here’s the thing about collective R&D. It isn’t pretty. Just like science, a lot of times, things don’t work out right at first and sometimes they never do. But you learn a lot as you try to fix them. We are all working through this together and these things will be awesome and foolproof one day, but you are an early adopter. You have my promise that these #%#$%@ things can work, have worked, do work. We just need to find the problem with yours. Deep breath.

It is so much easier to SEE what should be adjusted. If after following these instructions you are still having problems, PLEASE CREATE A NEW POST AND UPLOAD PICTURES OF THE PARTS YOU ARE TALKING ABOUT, TAG IT AIRLIFT TROUBLESHOOTING, & THEN JUST LINK TO YOUR POST in the comments below.

1) Please make sure you have the latest version of the how-to for the airlift system. Updates (like software updates) have been made to the instructions. The updates were made to correct issues that we found people were running into. The file should be called “3plantairliftHOWTO_3_4_10.pdf”.

2) Pump- Get the PETCO Air Pump 2-Way For 13-106 gallon Aquariums Model 9903 http://www.petco.com/product/109838/PETCO-Air-Pump.aspx

3) Tubing-
Get it at Canal Rubber.
x1 3/8″ OUTSIDE DIAMETER 1/4″ Inside Diameter Reinforced Kuritec Tubing at 4′6″ long
X2 1/4″ O.D. 1/8″ I.D. Vinyl tubing at 2′6″ long
x1 3/8″ O.D. 1/4″ ID Vinyl tubing at 6′ long

4) One-way air valves-You need these. Trust me. If you get the Petco pump, these come with it for free! Otherwise, you need to go to an aquarium store and tell them you want one way check valves for an air pump. They will cost about $3 each. You need to insert these in the line between the pump and your windowfarm. Be sure they are facing the right way (blow thru them to test) and turn on the pump with your valves inserted before you insert the tubing in water. Otherwise, your air tubes might fill with water and your system will not pump as high.

5) Bottom reservoir- You want your airlift tube submerged under the tallest possible column of water. That’s just how to physics work. So, if you use the 1 Gallon Poland Springs bottle, fill it up as high as possible. If you use something else, make sure you have picked a container that is going to create a tall column. By the same token, if your tube is curling so that it is effectively not submerged under a tall column, zip tie it to something rigid to straighten it out and create the max submersion height.

6) Angled bottom to tube- Cut your water intake tube (the Reinforced 3/8″ OUTSIDE DIAMETER 1/4″ Inside Diameter) at an angle at the bottom so that it does not just suck on the bottom of your reservoir.

7) More teflon plumber’s tape at the joints- you may have a leak somewhere.

Bad air valve? We have had a quality control issue with the air valves on occasion. Take the out. Blow through them. Is one harder to blow through than the other? If so, replace or try cleaning/soaking in alcohol.

9) Smoother interior walls for your tube and rigidity- If you’ve tried all of these things and they don’t work, go to canal plastics and get some rigid acrylic tube with a 1/4″ inside diameter and 3/8″ outside diameter. Go to canal rubber and get some vinyl tubing with a 3/8″ inside diameter (for a curved u back into the column at the top). Replace the reinforced tubing with this more rigid and smoother walled tube. It is what we are using for the next generation windowfarms . . . coming soon in kits.

I’m attempting to build a version of the Airlift Window Farm without plastic parts.

The initial version uses stainless steel tumblers, sisal rope, metal crimps, a glass reservoir, and natural latex tubing. The only plastic part is the air pump. Everything was purchased fairly inexpensively (mostly on the Bowery in NYC).

You can find images of the project in progress HERE.

If I can get this one to work, I will build a second system next to this one using Chinese bottle gourds, coated in beeswax (see diagram). We’ll see.

PROBLEMS:

1. I’m currently having problems getting the pump to push the water up the airlift tube. I’ve noticed others have had this problem and see that Britta posted some suggestions, which I tried– but they haven’t worked. The air forced into the air lift tube doesn’t seem strong enough to move the water up vertically. It goes for about 6 inches and falls back down again. It also makes a loud bubbling/spattering noise. The pump tubes are dry and the air lift tube is fully submerged and mostly straight. I have an ActiveAqua AAPA7.8L pump. — ANY SUGGESTIONS?