Wednesday, March 2, 2011

Setting Up My Second Column - Week 3

February 5, 2011

 Here is an update on my first column:

My bean is flowering!

Lanky Broccoli

Close up of the broccoli stem, kinky... hahaha. You can see the residue from the spray of nutrients.

Roma Tomato
 Does anyone know why my tomato is discolouring? The edges of the leaf are crispy and look like they have been burnt or something.

Bean plant

Swiss Chard "Bright Lights"

The 3" net pots are too big to fit in the 1.5L bottles, so I ended up cutting them and using some zip-ties to make the basket a little smaller.

Close up of the modified net pot in the bottle. You can see my impatient paint job.

I have started adding hydrogen peroxide to the nutrients.

OK, now for the new column. Instead of painting the bottles, I used white duct tape. Painting takes so long, and it has been really cold outside, so breaking out the ole' rattle can was not a top priority.

Also note the white stuff inside the bottle.

This is a close up of the brand of tape i used.

I took a trip to the local hydroponics store and I was asking about smaller net pots (the only size smaller is 2" which are puny). When I mentioned that I am using a vertical drip system, the salesman offered me a trial pack of this fluffy plastic medium. Seeing as it was free, and in the spirit of R&D, I am going to try it out.

This stuff is called "STG Storm Series Tempest."

It says on the package that it is designed for all types of hydroponics including drip systems.

This is a close up of the product. It is a 4" diameter column, and it has a square chunk taken out of it to accommodate a rock wool cube or the like.

Because I have been having problems with the net pots, I decided to just squish one of these into each bottle.

They do not hold water at all, so I have to be vigilant in ensuring my airlift is operational at all times or I will have very sad plants.

I purchased a 10L water jug, which I was intending to use as a reservoir.

During the installation, however, I decided that a 2L pop bottle fits way easier underneath the second column.

I have been using this as a holding tank for the water as I let it sit and de-chlorinate.

Here is a close up of some brass chain that I used to suspend the column. Instead of strapping the bottles to a post, I hung this column from the rack that I purchased from Ikea.

I used a soldering iron to melt two holes into the sides of each bottle near the top. Then I threaded the brass chain through each set of holes.

I apologize for the blurry photo, this is just a close up of how I suspended the column. The chain came with some couplings and links, and I used two of them to secure the loop at the top of each chain.

You can sort of see the way I threaded the bottles from this shot as well.

Here are the supplies that I purchased from a pet store for use in hooking up my air pump to supply two airlifts.

This is a package of T connectors that I use to combine the water and air in the reservoir as well as to split the airline from the air pump.

This is the valve I use to control the amount of air going into each airlift.

I have been most successful in having a stable airlift when I use this valve to significantly reduce the amount of air going into the air lift.

When you watch the connection underwater, the bubble of air builds up and fills the water intake tube until there is enough air to lift the column of water (which is dependent on submergence).

This is the check valve that is placed in between the control valve and the T connector in the reservoir.

Using this is very important! I am very glad that I installed these, as when I am experimenting with the airlift, sometimes the water flows back to the pump and this is the only thing stopping my pump from getting ruined.

I think this was only around 4$. Way cheaper than replacing the air pump.

Below is a close up of the part of the airlift that is submerged in the reservoir. The coil is a few feet long and secured with zip ties to make changing the nutrients easy. The airline from the pump and the line that travels to the top of the column make up the other 2/3 of the T.

This is how the whole thing sits in the bottom of the reservoir.

After filling the bottle with water and testing the system, I had problems keeping the coil seated on the bottom of the reservoir.

To fix this problem I cut the zip ties and made the coil a bit smaller than the diameter of the bottle. This way I can wedge the coil into the bottle to stop the air from lifting it to the surface of the reservoir.

So here is a shot of my first column's airlift system.

You can see the basic arrangement of tubes.

The line going out the T connector to the top of the photo is is main airlift tube to the top of the column



 Here is a shot of the airlift during testing. I have cut a hole into the side of the bottle, which allows the big coil to be put into the bottle.


 You can see the valve on the left next to the pump. Also, note that the coil is smooshed into the bottom of the reservoir.

This is the setup that I used to split the air from the air pump.

I use the valves to restrict the air flow, so very little air goes through either side.

This is a bit of a balancing act, and takes a bit of tinkering to get both airlifts working well.

There you have it! My completed second column. I purchased some shoe racks to raise my window farm up a bit so that I can use the bottom bottle. It worked out very well as the legs from my frame fit perfectly into the holes in the shelves and make the whole thing very stable.

 Feel free to send me your questions and comments. I look forward to hearing from you!

- Melissa


  1. Hi Melissa, I think you did very well. I think you should consider this alternative. You know those plant watering tops to go on pop bottles? They are red or green and have about an inch of plastic between the top and its little shower head. Just cut off the showerhead, attach it to an upside down pop bottle as the reservoir of you windowfarm. Then attach your tube and have the t joint attached to that tube.

  2. @Brian White

    Thanks for the comment Brian!! I have tried to use the bottle top waterers, but the problem is they only fit on 2L bottles. They are a bit too big for the 1.5L bottles that I am using in my windowfarm.

    I am using one of them (the weeder tip without the black tip) as a funnel on the bottom of my first column to help direct the nutrients back into the reservoir.

    Thank you so much for your youtube videos on submergance... using a T instead of that whole air needle setup is way easier. I have learned a lot from your videos!!

  3. @Brian White

    I just re-read your post, and I think I will experiment with your suggestion. How would you connect the reservoir to the column?

    Would you use a 2L that is upside down with a hole in the bottom of the bottle that is connected to the last bottle in the column?

    In other words would you suspend the reservoir? Or maybe would you create a stand for it? I am just worried about weight concerns.

  4. Can you please email me the materials needed to start this project? I needed it ASAP i am doing a challenge project for school and I want to be able to improve the window farm and share my ideas.

  5. I am a newbie on windowfarms and since I started to read, this is the best explanation of an airlift system. Thank you!

  6. Sorry, melissa. Just a question. Do you know the power of your pump? I've seen some of them on internet: 3W-1output and 5W-2otumputs. Is this enought? Thanks!

  7. @ Ramon:

    I'm glad that this helps! I know I was really confused and it took lots of trial and error to figure out the airlift.

    I do not know the power of the air pump... but it was from this .

    Honestly though, I barely allow the air to enter the airlift, I find that if you connect the airpump to the airlift and allow it to go full blast it is too turbulent and the water doesn't move up the column smoothly.

    I think any airpump would work, although I am not an expert by any means. Restricting a powerful pump may wear out the motor?

    Anyways, I hope this helps. Let me know if you need more clarification.


  8. Your tutorial really is the best one I have come across, thank you. I also find the tiniest bit of air works well. I'm trying to set up 2 colums with one reservoir now and my question is:why when i turn the air up to much dose it shoot out the bundle of air tube some times and other times out the top. I realize its going to take patience but i thought maybe i'm overlooking something.

  9. @holman,

    I have been trying to figure this out as well. It seems that the air will bubble out the coil if that tube isn't long enough for the 'downstroke' of the airlift. Also, sometimes it seems to do it just for the sake of driving you insane.

    I have started tinkering with another airlift design, and hopefully this one won't have the problems of air backing up into the reservoir.

    Wish I could give you a definitive answer about it, but it is a problem for me as well. One thing I have noticed is that it seems to find a happy medium eventually. I only get the blowback when I start tinkering with it. One member on suggested that the airlift does need some time to regulate itself and find a rythym.

    Give me a shout if you find a pattern of why it works, I am interested in any insights.


  10. thanks for you insightful tutorial! i'm still trying to figure out how to balance the two airlift lines - i can't seem to get a stable two line setup.. the water always chooses one path and sticks to it.
    oh, and i also made a (tiny) improvement: instead of the tube coil, i use submerged check valves that prevent bubbling out on the wrong side.

  11. @Anonymous

    The check valve thing sounds good, my only concern is the check valves I'm using have a metal coil... it might get rusty? Or clogged with salts?

    Let me know if it works out!!

    I've since revised my design and no longer need to do a coil in the bottle!

  12. Hey Melissa,

    Just wondering if you can share your design modification that gets rid of the coil.

    1. Sam,
      I just posted my new design if you're interested.

  13. what tubing are you using melissa?

    1. I was using airline tubing for aquariums, but I have since switched to black tubing (also for aquariums). It's really soft and flexible... and inexpensive!


  14. I am REALLY new at this... and struggling-- any chance you can help me out?

    First, thanks very much for your post here.

    I have a splitter, but can't get water to go into the tube with the air. I don't yet have a coil, just a short tube (I've also tried with a one-way air thing on the end). What does the coil do? Is is essential? How does the water get sucked up that long coil?

    Is this a science phenomenon I missed in school?


  15. I am going to start building a WM together with a bunch of friends, and came across your blog when trying to figure out the best way to make the tube assembly in the resevoir. The t-connector-solutions seems like a vey simple way to go, but you are writing in one of your comments here, that you got rid of the coil - would it be possible for you to share your solution? :)


    1. Hi Rene,

      I just posted a quick picture of my new airlift design... I hope it makes sense.


  16. I have tried the v3 original airlift and bought the rigid tubing etc. have a Petco 4 outlet adjustable pump as they suggested in parts list. I also tried the T w the drooping loop and still occasionally get air backed up into reservoir. I also tried diff diameter air line tubing. All same results w air backing up with timer restarts.
    Solution: I bought 1/2" plumbing rubber washer, made middle hole large enough to fit air tubing thru it snugly, put this into the flip top cap for the reservoir. Then have 1.5" Max tubing coming out of the flip top cap as a water drain. I connected an flow regulator that is gaped like an elbow to give a 90 degree angle. Then unconnected a few inches of tubing to the out part of the regulator which goes to a tee at the height of the cap. I connected the air pump tubing e check valerie and the air lift tubing to it. Pump on lowest setting. 6 bottles for plants and one for reservoir is used. When the pump turns back on, the air no longer backs up into the reservoir from the air kick that was happening before even w pump at lowest setting. I pinned the pic of what the tubing and regulator looks like on the reservoir bottle on pininterest under hydroponics and karen sabolcik. Hope this helps. This issue was driving me nuts for two days!

  17. Sorry iPhone autocorrect!! Corrections:
    Gaped - shaped
    E check Valerie - with a check valve
    Each row has 6 plant bottles and one reservoir. There will eventually be 6 rows and two air pumps.

  18. Hi, Melissa, Just looking at this again a few years later. I have done something where I used about 10 inches of tubing with a "constriction" at the end instead of your coil and it really works well. The constriction is the key. Another important part is having the airspeed controlled with a tap. I have achieved extraordinary lift to submergence ratios with this method. Up to 20 to 1 lift to submergence. Here is a link to a diagram. In my case it was a drywall bucket or paint bucket. About 5 gallons or 20 litre size. 14 inches high or 34 cm high. Thanks Brian