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VPD Calculator

Vapor Pressure Deficit (VPD) describes the difference between the current and maximum water vapor content of the air. The heatmap shows you at a glance which combination of temperature and humidity is optimal for your growth stage.

Settings
15°C35°C
20%90%
-5°C+2°C

Vapor Pressure Deficit

0.91 kPa

Optimal

VPD is optimal for the Vegetative phase.

Strain Recommendations

Indica
indica

Indica strains prefer slightly higher humidity and a lower VPD value. They are more sensitive to dry conditions.

Optimal VPD: 0.70 – 1.10 kPa
  • •Maintain higher humidity than with other strains
  • •Ensure good air circulation to prevent mold at high humidity
  • •Slowly increase VPD during bloom phase to minimize stress
Sativa
sativa

Sativa strains tolerate drier conditions and a higher VPD value. They often originate from tropical regions with strong transpiration.

Optimal VPD: 0.90 – 1.30 kPa
  • •Use tolerance for drier conditions to promote vigorous growth
  • •Plan for a longer bloom phase and adjust VPD values accordingly
  • •Ensure sufficient watering, as higher VPD means more transpiration
Autoflower
autoflower

Autoflower strains have a shorter life cycle and less error tolerance. Stable environmental conditions are especially important.

Optimal VPD: 0.80 – 1.20 kPa
  • •Stable VPD values are more important than with photoperiodic strains
  • •Less error tolerance — deviations affect yield more quickly
  • •Account for shorter seedling phase and transition quickly to vegetative range
CBD
cbd

CBD strains are often more robust and tolerate slight fluctuations better. A slightly lower VPD can positively influence the terpene profile.

Optimal VPD: 0.75 – 1.15 kPa
  • •More robust against fluctuations than THC-dominant strains
  • •Slightly lower VPD can positively influence the terpene profile
  • •Consistent conditions promote a balanced cannabinoid ratio