Light intensity is very important because it is one of the limiting factors which determines your growth rate. If your light intensity is too weak you can have loose, airy buds and leggy stems, even desiccated plants. If your light intensity is too bright, you can have bleached buds, burnt leaves, and stunted growth. Optimizing your light intensity is the best way to keep your ganja growing at its best.
Lighting requirements at different stages
The light intensity a plant requires is going to vary depending on its point in the growth cycle and not necessarily by its age. A mother plant for example, is not going to require as much light as a plant in bloom, even though it is bigger and bushier than the flowering plant. Knowing the stage of life the plant is in is the first step to determining the light intensity it requires. We have listed below the correct intensities you should expect at each stage in the growth cycle.
Cloning PAR levels: 50-150
Clones will not need as much light as the other growth stages. Clones are very sensitive to light and you want to discourage all foliage growth in an attempt to transfer as much energy as you can towards the creation of roots.
Seedling PAR levels: 200-600
Seedlings can take a bit more light than clones. Seedlings will start with roots so you want them to be adapted to the vegetative light intensity. If the light intensity is too low the seedlings will stretch, but if it is too high they can shrivel and die.
Veg PAR levels: 200-600
For vegetative growth we recommend 200-600 PPFD. This is the sweet spot between giving too much light and not enough. Too much light can damage the plants but too little can cause the stems to stretch causing internodal spacing. Decreasing the amount of plant stretch while not damaging the plant is the ultimate goal.
Flower Par levels: 300-1200
Flower is the stage where you want the most light possible, averaging around 900 PPFD. If you are looking for the best yields 900-1200 PPFD with CO2 supplementation is recommended.