Vapour-pressure deficit the plant may dry out and die. For this reason the ideal range for VPD in a greenhouse is from 0.45 kPa to 1.25 kPa, ideally sitting at around 0.85 kPa. As a general rule, most plants grow well at VPDs of between 0.8 and 0.95 kPa. In ecology, it is the difference between the actual water vapour pressure and the saturation water vapour pressure at a particular temperature. Unlike relative humidity, vapour-pressure deficit has a simple nearly straight-line relationship to the rate of evapotranspiration and other measures of evaporation. To compute the VPD, we need the ambient (greenhouse) air
Water of Life (Christianity) Water of Life (Christianity) In Christianity the term "water of Life" ( "hydōr zōēs") is used in the context of "living water", specific references appearing in the Book of Revelation ( and ), as well as the Gospel of John. In these references, the term "Water of Life" refers to the Holy Spirit. The passages that comprise are sometimes referred to as the Water of Life Discourse. These references in the Gospel of John are also interpreted as the "Water of Life". The term is also used when water is poured during Baptismal prayers, praying for the Holy Spirit, e.g.,