Definition - What does Growstone mean?
Growstone is a commercially available hydroponic growing medium made of recycled glass. The glass is completely broken down into small, smooth pieces that can be easily worked with.
In addition, this material is inert, so it doesn't supply plants with any additional inputs or elements that could interfere with the nutrient solution in the system.
MaximumYield explains Growstone
In hydroponic gardening, there has to be some way to anchor the plants as the nutrient solution flows. Sometimes this is done by planting through holes drilled in the top of PVC piping, other times the plants are planted into an inert material commonly called a grow medium or substrate.
When hydroponics first entered into common practice, sand or clay pebbles were most often used as the grow medium, but today, products like Growstone, coco coir, and rockwool are becoming highly favorable grow mediums as well.
The growing medium that holds the plants in the growing tray should not contain any nutrients, as it's better if the plant is fed its entire life by the nutrient solution flowing over its roots. Instead of supplying nutrients, the whole purpose of the growing medium is to hold down the plants so they’re not swept away with the flowing nutrient solution. Because Growstone is made entirely out recycled glass, it is completely inert and perfect for this job.
Growstone is highly porous, allowing it to provide a lot of aeration to the roots. It is also lightweight, non-degradable, and made completely of recycled materials. Because it is made from glass, it is non-toxic and guaranteed to be free of contaminants like pathogens.
Growstones have no effect on the pH of the garden and does not compact, so roots never suffer. Growstones are also popular due to the fact they can be reused or further recycled, doing no damage to the planet.