Maximum Yield USA 2012 September | Page 79

Potting soil is also reusable and compostable, and while durable hydroponic media does not compost in the traditional way, it can be run through the process alongside organic material to form a pre-amended compost material. Even some questionable media can be salvaged though a process known as soil solarization—gnats in particular can be successfully treated with this method. Higher temperatures...will semi-sterilize the media within a few hours, killing most friendly and pathogenic microflora alike. Place the media in a closed black plastic garbage bag and cover with a clear plastic tarp tent. Allow to sit in the summer sun for several days. Internal temperatures can be checked with a compost thermometer. Peak temperatures of over 120ºF for a couple of weeks is hot enough to kill many weed seeds and garden pests. Higher temperatures (160ºF is often easily obtained in sunny areas) will semi-sterilize the media within a few hours, killing most friendly and pathogenic microflora alike. Media semi-sterilized in this method should have beneficial bacteria and fungi reintroduced after treatment, or mixed with inoculated soil before use. Indeed, adding additional nutrients and other enhancements to the composed media can improve the quality of the media and reduce the amount of additional nutrients that will have to be added during the Maximum Yield USA | September 2012 77