Science fiction movies often portray horticulture in the future, be it terrestrial or aboard spacecraft, with hydroponic gardens overflowing with leafy greens and brightly colored fruit. There is no soil, just clear water that hints at future-people creating a utopia of plant strains untethered from their earthly roots.
This star-faring food production method is not fiction if you forego the polycarbonate tubing, neon accent lights, and gardening robots. For his 2020 Hackaday Prize entry, [AVR] shares how he creates a bed for sixteen plants with parts sourced at a nearby home-improvement store. It may lack the visual pizzaz of the Hollywood versions, but it will grow soil-less crops on a hacker budget.
The starting point for this build is a sturdy wooden base. The PVC tubing and fence parts on top are light, but the water inside them will get heavy, and if you grow large plants, they become surprisingly heavy. Speaking of water, the sub-category of hydroponics this falls under is Nutrient Film Technique, or NFT, which uses a shallow stream of water laden with all the nutrients for plant growth. The square fence posts provide a flat top for mounting mesh cups where the plants grow and a flat bottom where the stream continuously flows. A basin and pump keep the plants refreshed and fed until they are ready for harvest.
Microgreens, also known as vegetable confetti, are all the rage in fancy restaurants around the globe. Raised from a variety of different vegetable seeds, they’re harvested just past the sprout period, but before they would qualify as baby greens – usually 10-14 days after planting. There’s a variety of ways to grow microgreens, and [Mr Ben] has developed a 3D printed rig to help.
The rig consists of two parts – a seed tray and a water tray underneath. The seed tray consists of a grid to house the broccoli seeds to be grown, with small holes in each grid pocket to allow drainage. They’re sized just under the minimum seed size to avoid the seeds falling through, and also provide a path for root growth. Beneath the seed tray, the water tray provides the required hydration for plant growth, and helps train the roots downward.
[Mr Ben] notes there are some possible improvements to the design. He suggests PETG would be the ideal filament to use for the prints, as it is foodsafe unlike PLA and ABS. Additionally, precautions could be taken to better seal the water tray to avoid it becoming a breeding ground for insects.
Overall, it’s a tidy project that makes growing these otherwise delicate and expensive greens much neater and tidier. There’s also plenty of scope out there to automate plant care, too. Video after the break.
Continue reading “Germinate Seeds With The Help Of 3D Printing”
[Todd Christell] grows tomatoes in hydroponic buckets in his backyard, and recently he suffered a crop loss when a mechanical timer failed to dispense the nutrient flow as directed. He decided the solution was to add a sensor array to his home network.
[Todd]’s home automation setup runs on a Raspberry Pi loaded with Jessie OS and Node-Red, with Mosquitto as his MQTT message broker. With a sensor network in place, [Todd] would get updates on his phone alerting him if there was a problem with the pumps or if the nutrient bath was getting too low.
The proposed hydroponic setup would consist of an ESP8266-12 equipped with a DS18B20 waterproof temperature sensor, a reed sensor detecting nutrient levels, and a relay board triggering one pump to fill the grow buckets from the main sump and another to top off the sump with the solution from a reserve tank. One early problem he encountered was the electric fence (pictured above) that he employs to keep squirrels away from his tomatoes, interfered with the ESP8266’s signal.
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?
When operating any kind of hydroponic farming, there are a number of lighting solutions — few of them inexpensive. Originally looking for an alternative to the lighting of IKEA’s expensive hydroponics system, [Professor Fartsparkle] and their colleague prototyped a rail system that allows clip-on LED boards for variable lighting options.
Taking inspiration from wire and track lighting systems, the key was the 5mm fuse holders mounted on the bottom of the LED boards. Snipping off their stopping clip makes them easy to install and remove from the mounting rails. The rails themselves double as power conduits for the LED boards, but keeping them out of the way is easily done with the variety of 3D printed hangers [Professor Fartsparkle] has devised. Lighting is controlled by a potentiometer on the power injection board, as well as any home automation control via an ESP8266.
[Professor Fartsparkle] asserts that the boards can be slid along the rails without any noticeable flickering, but they do suffer from heat dissipation issues. That aside, the prototype works well enough that the 3W LEDs can be run at half power.
This is an ingenious — and cheap — workaround for when sunlight isn’t an option, but you are still looking for a solution capable of automation.
With winter on the way, our thoughts turn to indoor hacks. And what could be better in the cold winter than fresh veggies? This can be done by replacing the sun with an LED light, and [Margaret Johnson], aka [Bitknitting] has been working on building her own LED plant light.
She’s using a combination of red and blue LEDs that produce the ratio of light frequencies that plants thrive on, and has been experimenting with how bright to make them and how long to run them. This combination of factors determines how much light the plants get every day, called the Daily Light Integral, or DLI, and has a huge effect on how well the plants grow.
Her latest prototype uses nine red and two blue 3 Watt LEDs which run for about twenty hours a day. These lights shine onto the growing area, a bucket filled with nutrient solution. [Margaret] has done an excellent job of outlining why and how she made the choices she did and providing lots of links to more information for the home grower. It’s a great place to start for anyone looking to get something growing indoors in the depths of winter.
This team project for the Hackaday Prize is a solution to a rather important problem. Imagine growing plants for use as biomarkers for pollution. It’s a great idea, but how do you grow the plants in the first place? This team is building a space-saving hydroponic system that packs the most green into the least amount of space. It’s simple, and can be built almost entirely with parts from the local home supply store.
The design of this hydroponic system is based on a few PVC pipes, arranged vertically, joined together with a few 90 degree bends. In each course of pipe, a few holes are drilled to accept a plastic cup. This cup is filled with some sort of growing medium, and the Genuino-based controller takes care of everything else. Watering the plants, turning the lights on and off, and recording the nutrient concentration of the water is all possible with a simple microcontroller.
Right now the team has a huge stack of perforated PVC pipe and a Genuino-based brain box that takes care of everything plants need. It’s going to take a bit of time for the plants to grow, but this is still one of the most compact hydroponic systems we’ve seen.
You can check out a video of the entire setup below.
Continue reading “Hackaday Prize Entry: Automated Hydroponics”