VPD Calculator
A VPD chart combines leaf temperature, room temperature and humidity into a single unit of pressure. If all values are in harmony, the plant can fully develop its genetic potential. Both too high or too low VPD values lead to stress for the plant.
In the flowering phase, a VPD of 0.7 - 0.9 kPa with relative humidity > 60% can be set consistently, if Purolyt is applied regularly throughout the entire cultivation cycle. This results in significant yield increase.
| Conventional VPD values |
VPD (kPa) |
| Low transpiration (propagation / early vegetative growth) |
0.4 - 0.8 |
| Healthy transpiration (late vegetative / early flowering stage) |
0.8 - 1.2 |
| High transpiration (mid to late flowering) |
1.2 - 1.6 |
| Danger zone (over / under transpiration) |
<0.4 / >1.6 |