Cannabis glossary

PPFD is the number of photons in the 400–700 nm range that reach a square metre per second, crucial for plant growth.

Definition: RDWC, or Recirculating Deep Water Culture, is a hydroponic system where cannabis plants grow in oxygenated, nutrient-rich water.

RH (relative humidity) is the percentage of water vapour present in the air compared to the maximum amount the air can hold at a given temperature.

Rockwool/stonewool is a man-made growing medium made from spun basalt rock and is commonly used in hydroponic cannabis cultivation.

Runoff is the excess water that flows over the surface of the soil after irrigation or rainfall, often seen in cannabis cultivation.

Definition: Silica is a compound made of silicon and oxygen, commonly present in soil and used to improve plant growth and structure.

Soil is a natural, organic medium essential for plant growth, including cannabis cultivation.

Super soil is a nutrient-rich soil mix used to grow cannabis without additional fertilizers.

Temperature (day/night) refers to the ambient temperature during the day and night affecting cannabis growth.

Vermiculite is a naturally occurring mineral used in horticulture for its ability to retain moisture and improve soil aeration.

VPD (Vapor Pressure Deficit) is the difference between the amount of moisture in the air and how much moisture the air can hold when it is saturated.

Worm castings are nutrient-rich excretions from earthworms, commonly used to enhance soil and plant growth.