Manufacturing Process The Growstone Eco-engineering Process Growstone’s patented manufacturing process takes waste glass from the landfill and recycles it into customizable products ranging from substrates for advanced hydroponic growing systems to soil amendments to improve soil structure and texture. The first step in the process is crushing the glass bottles into small pieces then into an extremely soft powder. It’s so soft, it feels like flour. That’s because the average particle size of the “flour” is one-fifth the size of a human hair. The “flour” or soda lime silica glass powder is the main component (up to 98%) of Growstone materials. Natural foaming agents and additives customize the material’s properties for different applications. Customization can create a material characterized by open or closed pore structure, with higher or lower water holding capacity and air-filled porosity, harder or softer. In all cases, Growstones rigid foam does not breakdown over time and can be re-used. After the material has been blended for the specific product application, it is dropped on the conveyor belt that feeds the kiln. The material is then fired in a large kiln. The kiln can be heated either from the methane harvested from the landfill, or by using natural gas. The blend rises as it bakes and bubbles of gas released during the backing process follow a torturous path as they escape, creating a network of pore cells in the material creating a rigid and highly porous foam with the desired physical properties. Growstones physical characteristics can be customized for different products and product applications. The cell structure, cell size, particle size and particle size distribution can be controlled as needed. Once done baking, slightly more than an hour, the material comes out of the kiln on the conveyor belt to cool down. As soon as it reaches room temperature, the product cracks into smaller chunks. These chunks are then crushed into the desired sizes. Since our production facility is right in the landfill, no long distance transport of raw materials is necessary, saving thousands of gallons of fuel and significantly reducing our carbon footprint. The manufacturing process also does not use water at any stage, so the water footprint directly associated with the production of Growstones is zero. The results are high performance, chemical free, recycled, and non-toxic soil amendments and hydroponic substrates. Growstones are as good for your plants as they are for the planet.