Maximum Yield USA 2012 September | Page 148

creating novel hybrid hydroponic... designing and building an optimal system on your first attempt are infinitesimally small. It is imperative to recognize that improvement is always possible and the chance of failure shouldn’t be a stumbling block. Through failure we can gain insights that success does not yield. Success is knowing the properties of your substrates—Knowing the strengths and weaknesses of your media is of utmost importance. There are quite literally dozens of tests you can perform on your media to determine the properties of both the individual components and total mixed substrate. While a number of these tests require specialized, and often expensive, equipment to measure a particular property, many cheap tests can be done to an acceptable degree of precision to assure excellent growth results. In my opinion, the variable of utmost importance is the air-to-water ratio, which refers to the relative amounts of usable oxygen and water a substrate makes available to plant roots. It is important to strike a balance in the moisture level of the substrate between moderate aridity and total saturation to avoid root death due to lack of water or oxygen. As a rule, this can generally be accomplished by combining media with high water-holding capacity (e.g., coco, peat or rockwool) with media that have high air-filled porosity (e.g., expanded clay, glass foam or perlite). If you are looking for a greater degree of precision, a simple method for testing this ratio is to saturate your media mix, allow for complete drainage and then record the length of time it takes the media to dry to a certain standard (e.g., dryness at 2 in. depth below the surface). This result will allow you to gauge how often you will need to irrigate the media, providing your plant with a stage-appropriate nutrient solution. So, whether you easily find success or struggle to make progress in your attempts at hybrid hydroponics, you should always bear in mind that the goal is to always learn from your mistakes and to build a better growing system. MY 146 Maximum Yield USA | September 2012