How much PPFD cannabis plants need when growing indoor?

As we all know, Cannabis growing with difference stage; Seeding, Vegetation and flowering stages, Also difference stage needs difference spectrum, lights.

Generally, Below data can be reference :

Seeding stage  PPFD: 100-300 μmol/m2/s, and 18h of daily lights cycle

Vegetation stage  PPFD:300-600 μmol/m2/s, and 18h of daily lights cycle

Flowering stage  PPFD: 600-1000 μmol/m2/s, and 12h of daily lights cycle

Cannabis seedlings stage do not need much light, about 200-300μmol/m2/s PPFD level combined with (about) 18 hours of daily is sufficient. Small and fragile seedling tissues are easily overloaded and damaged by excessive light. Low light level makes the size of seedlings gradually increase to the extent that they can tolerate more light intensity.

During vegetative growth stage, the PPFD level of cannabis is usually 300-500 μmol/m2/s. Some growers will offer higher PPFD levels, about 600, although others may say that this level of PPFD is not really needed in vegetables. During vegetative growth, plants produce leaves, branches and roots, but do not produce buds.

In the late flowering stage, many growers hope that the maximum PPFD level will reach  about 1000μmol/m2/s