Growstone manufactures breakthrough, high-performance hydroponic aggregate media and soil aerator made from 100% recycled glass. They are a highly porous aggregate medium manufactured in an eco-friendly exclusive process that requires no water. Our kiln runs on landfill gasses which were previously flared off.
Our aggregates are engineered to provide an effective air to water ratio for superior results. Whether you grow hydroponically or in soilless mixes, Growstones high porosity improve aeration and drainage of the root zone, while retaining water. What’s more, Growstones are lightweight, with a bulk density below 0.20 g/cc.
Unlike perlite and Hydroton, the production of Growstones requires no destructive strip-mining or overseas shipping in energy guzzling tankers. They are an environmental and horticultural win-win from start to finish — and they are entirely made in the USA. For growers who want beautiful results and are conscious about how the products they choose are made, Growstones are an ideal choice bringing inspired growers inspirational results.
How do Growstones compare with Other Substrates?
Growstones are engineered for a specific ratio between water holding capacity (WHC) and air-filled porosity (AFP) at field capacity (i.e. after irrigation water has drained away). The large percentage of inner pores inside each individual aggregate assures a WHC of at least 30% by volume. The spaces between aggregates result in an AFP around 50% by volume. This combination leads to high aeration and drainage of the root zone even when Growstones are at full water retention capacity (field capacity). The result is a growing medium in which water holding capacity and air-filled porosity are not mutually exclusive.
The specific combination of moisture retention and aeration characteristic of Growstones, represent an enormous advantage over other substrates which maximize either water retention (mineral wool, sphagnum peat, or coco coir) or aeration (perlite, expanded clay, rice hulls).
Growstone’s Family of Products
GS-1 Hydro Stones – Hydroponic Substrate
Growstones have a higher air-filled porosity than mineral wool, coco coir or perlite, and a better water retention than expanded clay (Hydroton) or parboiled rice hulls. These characteristics are important for hydroponic and soil amendment applications.
- In hydroponics, the high air to water ratio, represent an enormous advantage as it delivers a highly steer able substrate, and enhances oxygenations and gas exchanges, necessary for vigorous root growth and plant development.
- In soil blending, soil amendment, and container gardening applications, Growstones increase aeration and drainage significantly more than perlite.
Higher oxygenation of roots than mineral wool, peat, coco coir or perlite, and better water retention capabilities than Hydroton and parboiled rice hulls, positions Growstones as a high performance and highly competitive substrate with the current industry standards.
“Growstones are going to replace expanded clay pellets for hydroponics and perlite for soil! We proudly sell Growstones!”
— The Interior Tomato, Duluth, MN