Another thing about lights:

The light spectrum is measured in KELVIN.

In the saltwater aquarium hobby we use lights that give a blue color. Think about it..... where are coral reefs? Under water. How many of you have ever been diving or snorkeling? Have you ever dove down 30 feet and looked up? What color is it? It's blue.

So we use lights with a Kelvin (K) number closer to the blue end.

For example a 10,000k (10k) bulb looks like bright white light to our eyes. This is used to simulate mid day bright sunlight on the corals - when the sun is high in the sky.

A 12,000k (12k) bulb is leaning more towards the blue end. It is still very bright white, but our eyes can detect the faintest amount of blue showing through. This would simulate morning sun.

A 14,000K (14k) bulb is starting to look sky blue. This would simulate very early morning sun low in the horizon, but coming up higher.

A 20,000k (20k) bulb is looking really blue and almost purple. This would simulate very deep water where all the light waves have been twisted and turned by the water depths to a very dark blueish purple.

So now let's thing about what kind of spectrum our plants need. They aren't under water, so the blue colors are out. Our plants are genetically wired to grow in the summer months when the sun is highest in the sky and brightest. Our plants are also genetically wired to grow about 6-7 months from seedling to finished buds. Think about how the light changes during that 6 month time from April through October. That is the typical growing season in North America. Weather you're growing roses, hay, wheat, beans, corn or MariJ.


We want to simulate direct sunlight. We're looking for a 6,500k bulb for vegging because that simulates the early and mid summer sun through the longest days of the summer. It's going to simulate those months from late April through late August.

Then as the sun drops into the southern sky in late August and into September, the light waves are going to change color because the sun is coming through our atmosphere at a much different angle relative to the Earth. The light waves must travel through more atmosphere and at a different angle than straight up overhead.

This change in lighting intensity, color spectrum and angle is what makes our plants trigger into the flowering stage.

This is when we want to use a bulb around 2,300k --- 2,700k, Those colors simulate the reds better. The same reds our plants would see if they were outside in September and early October. This is when the sun is very low in the southern sky. The light is traveling more sideways through the Earths atmosphere to reach our plants -- instead of directly down on them like back in mid June.

Think about the kind of light your plants need early on in their development, through the growth cycle 2-5 months in and again in the last few months of the cycle when they are flowering. The plants are genetically designed to grow between 5 - 7 months. In that time they are genetically wired to "seek" certain light colors.

We can't change the genetic make-up of our plants. They are wired for a certain light spectrum and they are wired for a certain time period. Give them the kind of light they need for as long as they need it --- you should end up with gobs and gobs and gobs and gobs and buckets and buckets of tasty buds to smoke. :stoned:

:thumbsup: