Volunteers Needed (Badly)


You are squandering your visitors!
You purport to be encouraging students to get interested in agriculture by starting with aeroponics.

If you actually want to encourage people at the very least you should be providing some information. It would be very easy to ask for volunteers to improve your site and wiki, but you could also run some competitions for various designs eg as below

However you have an appallingly uninformative website which redirects interested visitors to the even more obscure github. You haven’t even pinned important topics to the top of your forum! I’m actually shocked at how bad your website and design is, especially as you claim to be trying to get schools interested and you’re in MITs media lab.
For those who give up wasting their time with your website and search the web for “aeroponics for beginners” they are directed to a wealth of information helping them grow marijuana, so I’m sure most parents are going to be really keen to let their children start that!!!

You should be asking your visitors to contribute to the wiki and providing information on:-
*Simple aeroponic nutrition:
Why might you buy a commercial mix to start with and what not to get.
But optimal plant growth seems to require varying quantities of nutrients at each phase of growth. It should therefore be easier to modify and experiment (and cheaper) to work with provide a recipe so you can just mix up separate bottles of nitrogen, phosphate and potassium compounds and a micronutrient mix. You could then put them in separate syringes and use continuous rotation servos to automatically inject appropriate amounts into the mix as required ($2 for servo and 5mins to modify and a further 5mins to assemble into a functional automated syringe). This would be a great school project as it could involve measuring and mixing and chemistry, and some basic mechanics/electronics…
Searching google for “hydroponics nutrient recipe” seems to give a few starting ideas, but the mixes don’t quite provide this flexibility (and should aeroponics be different?)

*Aeroponics environment
Discussion around a beginners optimal setup.
What are good values for humidity, temperature, etc with reference to a simple “recipe” (don’t bury it in a database if you want people to be interested).
Don’t forget the importance of light - start by putting it on a window sill, but really whats wrong with using a desk lamp (as most people have one that would seem like a good place to start), but an LED fluorescent bulb can be had very cheaply now, or what about those colour changing LED strips, … (you get to teach about physics, economics, and botany simultaneously…)
What about EC and pH
What do you sacrifice by not controlling the leaves environment (ie having plants grow in room air)?
Then what changing CO2 and O2 contribute (and perhaps a discussion of tight vs loose root bundle promotion)
Stress usually makes leaves bitter (try tearing bits of a lettuce and see what it tastes like a few days later). Can you explain how to makes it sweeter?
And when the basics are there I’m sure there are a bunch of people out there who would like to try a java simulator to experiment/design/upload growing recipes too…

You should also have various aeroponics setups (with photos) - you could run competitions to get hobbyists designing these:-
*The simplest ever aeroponics setup (I think this would growing spouts in foam, but what else can you grow and eat with little or no effort?) What about growing a new lettuce from the base of an old one - although this is probably the simplest hydroponics setup it’s still a fun experiment.

*The 2nd simplest aeroponics setup (I think this would be just an icecream container and a fogger). This would get families interested if they could produce a lettuce or cucumber every week for a $5 outlay (plus nutrients - would it be possible to use fluid from composted food, or blend another vegetable and use the juice as a basic nutrient solution to make it even simpler?)

*The coolest: I’m imagining a usb powered aeroponic ‘plant pot’ which could be monitored from a tablet, that would be a tech-toy to get people interested. A dome could be made from the bottom of a soft-drink bottle, and blue/red LEDs would add extra coolness. DIY version $10-15/pot. (mine would definitely be used for growing everbearing strawberries)

*A reliable home vege factory - this should be able to simultaneously be able to grow a range of different veges eg strawberries (what wouldn’t get most kids interested), lettuce, cucumber, some herbs. Thus it probably needs 6-12 individually controlled growing locations to guarantee a continuous supply of vege. It would probably be best if it was low-profile and could sit on a window sill.

*A home research version, this could include more advanced tools, such as a simple weighing system to measure growth, or an RPi to monitor leaf density

On that note, I’m not sure why you are mucking about with Raspberry PIs, as very few people own them, and unless you’re using a webcam to monitor leaf colour or foliage density (which most people won’t need) they’re total overkill (and most people already have webcams/tablets/old phones which could do this anyway).
Arduino nanos can be had for around $2, and are more than capable of running and monitoring an aeroponics factory (after all the variables don’t change that fast), and for that price you could easily have one for each plant. If you want to link via I2C and add a bluetooth board for another $2 you can communicate with an Android tablet using MIT inventor and teach the basics of programming too. But seriously it is a cakewalk nowdays to have a generic host which runs on Android, IPad, PC, Mac and Linux and would easily graph values and modify recipes!!!

BTW an arduino can easily measure EC/TDS of a fluid for a few cents - if you are only measuring intermittently then DC measurements should be fine, but add a cheap H-bridge and you could easily switch to AC though.
Why don’t you just use stainless electrodes sitting in the fluid. If they corrode/coat then, put them in a small reservoir with a hole in the bottom. A $2 pump could fill this every 5 or 10 minutes (depending on how often you wanted to measure), the measurement could be made and the fluid would then drain away.)

What about use a simple piezo disk under each plant with a driver on the main circuit board. If this were possible you could have a disc under each plant to drive the fog into the root bundle

Or use a USB fogger so the peizo disk is separated from the electronics and the voltage/current remains low thus minimising/ avoiding use of multiple voltages in the system.
eg ebay item 401132954396

What about asking for novel designs for subcomponents rather than designing your own - there are hundreds of hobbyists around the world who like experimenting with stuff (that’s why Reprap really got going - Adrian got them involved early)
To separate the root bundle, what about a mesh cone. Place the seed at the tip and the roots grow outward and drop through the mesh to prevent too tight a root bundle (you could cover this with black plastic and place it over the peizo.

What about suspending the setup from a spring so you could measure the weight of the plant - you might even be able to use induction to measure the harmonic frequency and infer it from that rather than a sophisticated scale.

What about discussing the various pros/cons of humidity sensors in aeroponics eg resistive vs capacitive vs a laser/photodiode (all possible for consumers for $1-$2)

for pH: what about the redox principle of a lemon battery - this uses different electrodes (typically a galvanised (=zinc) nail and a penny(=copper)) to chemically generate a voltage from acidity in fruit. I would have thought this should work for any liquid solution enabling an arduino to measure the voltage for a cheap pH meter. (Obviously you would have to measure the EC first with identical electrodes then correct for changes in the ions in the solution). With these components you could easily replace/clean the electrodes or you could get a carbon electrode by cannibalizing a AAA battery.

You also need someone sensible to sort out your github. You only need 4 files in your root directory for the food computer:-

  1. the compiled host ready to install
  2. the arduino source code ready for compile/upload
  3. a bill of materials for the electronics
  4. graphic for the basic breadboard design
    everything else can be put in a subfolder so as not to confuse the interested newbies


Hello David, and welcome to the forum !
A lot of your issues are valid, but please consider yourself ‘one the members’ now and work with us to improve this forum. ( I am not related to MIT or those that have started this initiative, just a forum member like yourself )
You have many good ideas and thoughts, but it would be more helpful if you pet them, one-by-one, in seperate topics in the right category. Then others can respond to it in a meaningful way and contribute as well.
I have started on reorganising the categories so it will make it easier for people to find the information they are looking for, so it would be great if you could put your comments, ideas and suggestions in the right category for each topic.
Looking forward to reading your inputs !


Hi Ronald
I’ve realised I have to apologise, so thanks for a very moderate response, as it gave me the chance to think through the issue.
Essentially I was wrong - the website is absolutely fine for what it is intended - ie building a food computer which will ultimately be able to control large scale localised food production and can help optomise growing conditions for a range of plants. Unfortunately instead of quietly leaving like I’m sure most others did, I had a little rant.
My mistake was that (as I retrospectively realised) I arrived via Caleb’s Ted talk thinking the project’s purpose was to teach (rather than learn) about how plants grow and improve nutrition and that I might get something to eat out of it. I supposed I imagined building a small growing unit for home, something like a machine you filled up with water and added some ‘teabags’ of nutrients and a few weeks later could start harvesting.
Obviously when thought through, if I want lettuces at home in winter it is far more efficient to just buy some potting mix and put some seeds under a growlamp and rather foolish to build a complex machine to shave a week off the growth cycle.
Ultimately therefore thanks for the invite, but I shall currently remain one of the lost generation (I moved from a farm to become a doctor).
Cheers (and congrats to Caleb on a very motivating presentation)


Hi David, you are either very modern for a true member of the ‘lost generation’ or it was meaned as a metaphor…:slight_smile:
I am 52 years old and the OpenAG initiative is just one of the ways I can contribute to a better and healthier environment for my children. I know that the current design of the PFC is somewhat flawed and maybe too expensive to be a real solution, but consider it a starting point. If we can improve the PFC in a way that it becomes more user friendly and less energy consuming (or maybe find a way to re-use the lost energy) it could ignite somthing that changes the world (at least a bit) or changes the way we look at our food.
Many argue (see Calebs current twitter feed) that the energy consumption of the PFC makes it a useless exercise. I totaaly disagree as I think that the PFC should not be considered as an cheap alternative to supermarket food. It is a way of taking back responsibility for one of the most important aspects of our live: food.
I hope that one day (real) farmers will be able to connect again with their customers and get rid of the monopoly of the middleman (large retailers) which will only happen if farmers are able to produce in the proximity of the consumers (in the city). Hopefulle the PFC will contribute (a small bit) to this process…


Are energy costs of transport (both workers and produce) and storage being considered in that calculation?
Also if a device produces “waste heat” in a house which would otherwise be centrally heated in winter, is it actually waste heat? Also during summer sunlight may well replace grow lights for home produce and there are already organisations (restaurants etc) who grow food on their roof hydroponically without lights because they can better guarantee quality…

Also if you want to decrease the middle man, you will also need to consider methods of cloning or encouraging a plant to seed, and how to recycle nutrients (a home composter could save even more energy by not transporting waste).

(I’m acutally GenX, “lost gen” was referring to Caleb’s younger generation leaving the farms)


Still new to the forum, so i’m going through threads one by one. But even as someone new i feel i should respond to this as there are some good points to be considered.

First i should start out by saying that i am a bit confused as to why the OP posted this a rant rather than constructive suggestions, but i gather from his second post that he came in with some different expectations about what these devices are, the role the MIT team plays, and how big / involved the community is at this point.

I think, though i could be wrong that many of the things in here relating to hardware design and alternative methods will develop naturally as the community grows and expands. I plan to help that wherever i can, and is a good reason i just started a new thread titled “Alternative Hardware for DIY Food Computers” as i think these designs can always continue to improve. At the moment they are at the very beginning of a proof of concept design and need some polishing. But that will come in time, and as the community grows. Skimming the forum briefly it seems there is a little tinkering and mods going on here and there, but as a whole not much hacking or DIY designs yet. But not something i’m worried about.

As for lighting, and as someone who has tinkered a bit with trying to start seedlings indoors with a desk lamp, i can say that average desk lamps do not put out enough light that plants need. My next adventure is to go with the LED lighting of the appropriate wattage and the correct light spectrums (ie. red and blue).

CO2 control seems like an awesome idea for plant breeding. One thing i would like to use my future food computer for is for plant breeding for the climate on mars. I already have a few special plant varieties i’ve been working and breeding wiith for a few years that i think would do well on mars, they just need the time to adapt (maybe minimally) to the environment on mars. For example, Mars does have an atmosphere, although an extremely minimal one. There is CO2 present in abundance, actually 92% of the atmosphere is CO2, there is minimal oxygen, but plants don’t need oxygen, there is some Nitrogen, though limited in the atmosphere so legumulous plants that can fix their own nitrogen and carbon from the air would be a good place to start. I have a variety of pea i’ve been working with that i think would do well. aeroponics may or may not be the way to go on a mars atmosphere depending or what you are ultimately aiming for. There is simulated mars regolith soil that you can buy for relatively cheap for mars soil simulation. I actually bought some, but haven’t yet used it. It has a few metals in it that i don’t know would be good for growing food crops in. but should be fun for future experiments. One may need to add some UV LEDS to their food computer to simulate the high UV radiation on mars.

Though i am a big Arduino fan i can see the potential benefit of using Raspberry Pis over the Arduino for this project. By using a real computer you gain access to Linux and python. For the number of sensors and actuators and other things people want to do and hack with these i think the Raspberry Pi3 is the way to go on this one. 8 months ago perhaps Raspberry Pis were not as common, but today they are and are continuing to grow.

I was in the process of designing and building my own Electroconductivity Sensor/probe for another project before discovering the food computer since the commonly used educational Vernier sensors are bloody expensive. That design / build is about half way done. I just need to figure out the best way to place a connector (maybe i will 3d print something) and some conductive glue to attach wires to my tungsten electrodes. My design for this way aiming to be a dual use EC / Salinity Probe and a Electrolysis machine that could be used in third world countries to produce clean water by electrifying a little bit of salt water and splitting the salt into Chlorine to kill bacteria and viruses. (see WataSol for more info on this (https://livingwithregard.files.wordpress.com/2010/11/ecca_watasol-minard-10.jpg)). So at least for my dual purpose salinity probe i don’t think carbon or even stainless steel electrodes are really the best, though they might work for just a sensor. I don’t know if i would want that carbon leaching into the water or not as the plants could probably use that as a carbon source to grow.

I will add that i think the salininty probes need a small and non-changing distance from each other to get the best accuracy and the math formula used to calculate salinity / conductivity. So that’s why i dont think two simple nails and an arduino would be adequate for this. But i could be wrong. Maybe for a tinkerer that would be sufficient.

yes i agree on the piezo disk as the current one looks a bit iffy with that little board sticking out. Surely we can do better than that. Again, i realize that the first design was a hack in progress, and as we all continue to open hardware design i’m sure these things will improve. I’m opting for a 24v self contained ultrasonic transducer (fog machine) on mine. Maybe more than one all at different heights on a slant or a floatable one so that at changing water heights the water can still be turned into mist.

Anyway, that’s all my two cents. I realize that the OP did admit a mistake of some sort and probably will never visit the forum again. But he did have some good ideas, so i felt the need to reply.


Thanks @Peperoni and @BioLumo

This community is for learning together and open to all, the critics and dreamers alike. The comments are fair if the expectation was that you were coming to “yoda’s cave” but this project is not that. Its about collecting a motly crew of #nerdfarmers to see what we can do together. I chose to make our group’s work at the Media Lab open for everyone to use in all is glory and with all its warts with the hopes that it gets picked up and taken further faster then we can do on our own. As for TED…well…I guess they asked me to talk because they thought it was an “idea worth spreading”…not because I had enterprise ready solutions or answers that rival google search

I encourage you to lean in @dgm3333 if you want to make a change and lend us some of your passion - we need all the passionate people we can get