What is used and how they work together defines very important substrate characteristics such as root anchorage, water supply, nutrient retention, water level and air exchange. Basic nutrition, most growers are fairly familiar with and are comfortable talking about. But the physics behind the substrate, is less understood by many. Surprisingly, when explained properly, the physics behind substrates is quite interesting and different from what one might have expected.
BELOW FIND UNIVERSITY STUDIES, LARGE CORPORATE RESEARCH, NOT TO MENTION NOTES FROM THE EDITOR
Soluable Salt Ranges
Keeping up on your soluble salt range is important. Always have an instrument at hand to check your nutrient levels. The below chart is a general guide as to what levels are acceptable or not.
Electrical Conductivity (EC) of a solution is a measure of ionic compounds dissolved in water. Organic Nutrients are ionic compounds. Another name for ionic compounds is salts. Assuming the water had very little EC before you added the liquid fertilizer, measuring the EC will tell us how much fertilizer we have in our liquid. EC is commonly measured in milli-siemens (mS) and/or Total Dissolved Solids (TDS) expressed in Parts Per Million (PPM). Both will give you the same information of how much fertilizer is in your liquid. The EC and PPM are always in relation. So stating the EC and PPM is redundant. The relationship is 1 EC (measured in mS) = 650 PPM.
| Desireable | Permisable | Dangerous | |
| EC | .75-2 mS | 2-3 mS | 3 mS & ↑ |
| PPM | 500-1300 | 1300-2000 | 2000 & ↑ |
Biochar & Fungi Relationship
Cation Exchange Capacity Information Blurb
The total CEC is impacted by these factors:
Amount of active humus such as compost, Amount of passive humus such as Biochar, The pyrolysis method of the Biochar added, Was the Biochar activated and/or inoculated? The type and amount of microorganisms, and The overall pH
