Grow Media Problems
When water is abundant in the growing medium, roots easily absorb it. Roots use more energy to absorb more water as it becomes scarce. Finally, the point comes when the substrate retains more moisture than it surrenders, and the roots receive no water. A good growing medium readily yields its bank of stored water and nutrients. A poor medium does not pass enough nutrients to a plant’s roots. The more easily cannabis absorbs nutrients, the higher the yield.
The cation-exchange-capacity (CEC) of a growing medium is its capacity to hold cations that are available for uptake by the roots. The CEC is the number of cation charges held in 3.5 ounces or 100 cc of soil and is measured in milli-Equivalents (mEq) or Centi-Moles/kg on a scale from 0-100. CEC of 0 means the substrate holds no available cations for roots. CEC of 100 means the medium always holds cations available for root uptake. Growing mediums that carry a negative electrical charge are the best.
Visible Signs of Grow Medium Stress
- Dry, crispy, brittle leaves
- Patchy or inconsistent leaf color
- Yellow leaf edges that worsen
- Crispy, burnt leaf edges
- Chlorosis- yellowing between veins while veins remain green
- Irregular blotches on leaves
- Purple stems and leaf stems
- Leaf edges curl up or down
- Leaf tips curl down
- Super-soft pliable leaves
- Branch tips stop growing
- Leggy growth
Grow Media Problems