The Grow Cube / Grow Box is my entry for the 2016 Hackaday Prize. It is essentially a counter top / table top indoor hydroponic LED garden that you can use to plant edible vegetables.
The idea was to build a small unit that anyone can have in their home in order to always have fresh vegetables to eat. The Grow Cube would allow for the growing of micro-greens such as: rocket (arugula), garden & watercress, spinach, lettuce, other edible herbs and the like. Even a small tomato or pepper plant would most likely fit inside the box.
The only major limiting factor is the height of the box and the root structure that would develop in the 1020 trays.
The footprint of the Grow Cube is based around the popular 1020 Tray which is a very common seedling tray used in horticulture. It is slightly larger than its namesake of 10×20 inches (11″ x 21″) or approximately 55cm x 28cm. The Grow Cube’s outer dimensions therefore measure approximately 64cm x 35cm and has a height of 75cm (approximately 30″).
Since this is an indoor gardening box, natural light will not necessarily be available to the plants. As a result, artificial lighting must be provided. For this project, I’ve chosen to use 3W Full Spectrum Grow LEDs. According to the retailer, they cover the “Full Spectrum” that a plant uses for photosynthesis, primarily in the 660nm – 670nm wavelengths of the deep red and the 440nm – 450nm of deep blue.
The structure of the Grow Cube will be made out of light-weight 15mm x 15mm square Aluminium tubing that I will either braze solder or simply attach mechanically using either pop rivets or screws. The outer shell will most likely be white PVC foam board since it is also light weight and, being white, will have highly reflective surfaces for the light to propagate inside the grow chamber.
In terms of monitoring and automation, my initial idea was to monitor humidity levels and temperature. Something along the lines of a Soil Humidity Hygrometer might work to gauge the humidity level of the soil / growing medium. It would of course interface to either a micro-controller or to a single board computer and would control the pump for the water tank. The system will also turn on and off the lights and the fan automatically.
That is it for Part 1 of the 2016 Hackaday Prize Entry – Grow Cube. The next post will introduce the building of the Aluminium structure.