Hydroponics is an effective way of growing plants indoors through the use of water medium and artificial lighting. It often involves having a system to raise and lower the water level around the plants to let the roots breathe, however this can require some non-trivial plumbing. [Peter] wanted to instead explore the realm of wheel hydroponics to grow some ingredients for salad.
The idea is to have pods mounted on a rotating assembly, similar to the carriages on a Ferris Wheel. By rotating the wheel slowly, each pod spends a certain amount of time submerged, and a certain amount of time in free air. This allows the water level to remain constant and only the pods need to move.
The tank for the build is a simple plastic storage bin from a local hardware store, with the wheel assembled from various odds and ends and laser cut components, making this a build very possible for those with access to a hackerspace. A stepper motor provides the motive power, with the assembly completing approximately one rotation per hour.
[Peter] has run the device for several months now, noting that there are issues with certain plants maintaining their hold to the wheel, as well as algae growth in the water medium. There’s room for development but overall, it’s a great build and we hope [Peter] will be serving up some delicious fresh salads soon.
For another take, perhaps you’d like your hydroponics solar powered?
[Thanks Nils!]
This might work in space but then the dunk tank won’t. Most plants like our 1G in the same direction 24×7, roots down etc. The Ferris wheel is a good analogy as the passengers want to remain upright. This is like one of those wheels that start horizontal then goes to vertical. Huey, belch! Unfortunately this method messes with the central light idea. Then again the lights miss a light of space (and hence are dimmer) between each tray till things get bushy. Remember the inverse square law here. Spraying the roots is a third way that is popular in the covert crowd. Just raise the lights as things grow, constant lux.
What dark/light ratio do you use?
> This might work in space but then the dunk tank won’t. Most plants like our 1G in the same direction 24×7, roots
> down etc. The Ferris wheel is a good analogy as the passengers want to remain upright. This is like one of those
> wheels that start horizontal then goes to vertical.
I don’t get it. What are you talking about?
Think he is refering to wheels you stand in, in cubbies around rim. Wheel then spins fast enough for cetrifugal force to keep you in your cubbie as wheel tips up 90 degrees.
Think point was that plants don’t like being inverted. In a ferris wheel chair the pivots on the end keep passengers upright as big part goes round. Could be used for dipping plant trays, but central light wouldn’t shine on any plants on top side of rotation.
Gravitropism, roots depend on gravity to know in which direction to grow. Probably won’t be a big problem here because regardless of the directions the roots grow they’ll receive the nutrients and moisture they need.
Every plant has own internal gravity sensor. So seed know in which direction is good to grow roots into ground. Growing them upside-down is not best idea even if they are half of cycle in right orientation. It is not about growing in direction to light at all.
Perhaps you could fix the gravity thing by turning the wheel quickly enough (besides, there’d be much fun in the kitchen :-)
Might. Kind of defeats one of the purposes of hydroponics…space efficiency.
No thanks. I like my walls, and ceiling dry.
Deep Water Culture is what I use and it’s probably one of the easiest and cheapest forms of hydroponics, all you need is an aquarium air pump with a stone. For growing leafy greens the Kratky method is by far the lowest tech solution (requires zero power beside the lighting).
I agree. I have grown leafy greens, tomatoes, and peppers numerous times in a DWC system. Very little effort on my part and it works! The “Wick System” is probably the absolute easiest but you are pretty much limited to only small plants.
In space you could rotate the speed to get artifical gravity and a rotating bowl. Somthing like that
[img]http://i.imgur.com/rSxNWBB.png?1[/img]
Great work. Do you have any idea about the power consumption of the led source?
This contraption seems also to very space inefficient. If you want to explore the road of moving the plants and keeping the water level constant, I have another idea:
Mount the plant pods on a frame which can periodically sunk into the water and pulled out. Either by some ropes or chains on the corners or by a system on 4 knee-levers (one near each corner) which are connected by rods on each side and allow up/down movement of the frame.
Although I find it much more simple to change the water level in the tray (tidal system?). You need just a small pump and no more complicated moving parts.
Question: wouldn’t it be easier to implement an elevatory platform that cyclically raises the roots above the water? Much better than submitting plants to upside-down and low light conditions
Ideally you want the lights as close as possible without burning the plants, and with LEDs they’re not likely to burn. Inverse square and all that.
Spinning the plants around is weird and I don’t think the best way. Why not a reciprocating up-down motion, or simply a pump? There’s a lot of work being done, hydroponics is still a growing art, as ever, but the current knowledge is pretty good. Stick to the rules, they’ve been gained through experience and principle.
You want to minimize the amount of light that reaches the hydroponic solution, or algae will begin to grow in it. My experience has been that algae will throw the pH of the solution so far out of whack that plants have difficulty getting any nutrients out of the solution.
If you look further in his blog, he scrapped the project and moved to a more traditional setup. Interesting idea tho
https://lh3.googleusercontent.com/XDb7VwTjhoJqwvIiM0XKoFz-tk2oRsb5VvbrPToJJWzaOWcTIJsIXnR734AzS5rplSo=h900
use solar soil inestead
It’s certainly intriguing and I haven’t heard of a hydroponic wheel until now but I think that just sticking to a very basic, easy to build, and inexpensive DWC system is the best option for most people.