The Light Cycle of Cannabis
The cannabis cycle is one of the easiest to control and one of the most important factors contributing to the growth of cannabis. Like all plants, hemp relies on light as the basis for photosynthesis, which is the process by which plants produce food and energy. In the natural environment, hemp will change with the seasons in a specific environment. It will sprout, grow, bloom and show everything in response to changes in the environment.
In general, cannabis plants get more light during the vegetative phase and darker during the flowering cycle. Outdoors, cannabis seeds usually germinate in the spring and the sunshine hours in the spring begin to increase. They will keep growing until the days get shorter and shorter, and they bloom. Indoor, on the other hand, we must be the ones to regulate the light-dark cycle. Usually, a vegetative plant is given 18-20 hours of light and 4-6 hours of darkness. Instead, 12 hours of light and 12 hours of darkness are given during the flowering phase.
What is the spectrum of light?
The sun gives off energy in the form of solar radiation, these radiations are mostly filtered. Only a small portion of this light is visible to us humans, this portion is referred to as the spectrum of light.
Outdoors, cannabis plants grow under the sun, thus receiving the full spectrum of light. That is to say, indoors we must provide the best lamps grow cannabis with a spectrum of light as similar as possible for the best development of our cannabis seedling.
Cannabis in nature needs the blue wavelengths in the vegetative phase with the aim of growing strong, large and growing the greatest number of leaves. Cannabis in nature needs red wavelengths for flower formation during the flowering phase.
There is a large selection of grow lights, some with a better light spectrum than others, illustrated below.
Various Growing Lamps
If you’re growing indoors, you need to decide how best to set up your lights. As for the lighting system, there are many different options and many opinions. The intensity of the lighting system, the spectral colors and the underlying technology will vary. It depends on the size of the grow room, the power requirements and how much time and money you are willing to invest in lighting the grow room.
There are many types of grow lights, each of them with their own strengths and weaknesses. Many growers argue which lamp is best, but in general each lamp is designed specifically for a certain growth phase or type of job. It is up to the grower to decide how much money to invest and how much time in the lighting system.
HPS – [High pressure sodium vapor lamps]
HPS lamps grow cannabis have an ideal range of colors during the flowering period of cannabis plants, while metal halides are beneficial for the growing period of cannabis. They work similar to other HID lamps and emit light by triggering an electric current that flows through a bulb containing xenon gas and sodium gas. They will emit a dull pink glow and, once warm, will quickly turn into a pink orange glow. Furthermore, these lamps are particularly useful for indoor growth, especially for plants that are going through the flowering period.
The best option is to buy two 400w or 600w HPS lights – these lights will distribute the light evenly for your plants and there won’t be too many, so the risk of thermal damage is low. Note that you may want to use fluorescent and sodium vapor lamps at the same time.
LED – [Light-emitting diodes]
LED lights have many advantages. First, their voltage is very low, which means less money is spent on maintenance and electricity to keep them running. What follows is that they generate very little heat which means that if you use LED lights, you don’t have to worry about overheating the growth chamber. It can also further reduce dependence on ventilation and fans, thus further saving energy. In fact, depending on the operation, if you use LED lighting, it may be necessary to heat the room.
For growers who prioritize privacy, LED lights offer an added benefit: the reduced heat makes LED lighting nearly impossible to detect with the thermal imaging technology normally used to detect the infrared heat of most of the HPS lights. LED lighting is also quieter than other lighting options, without the background hum of HPS lights. The initial investment of LED lights is higher than some cheaper options, which may lead some growers to question their use. Assuming the room does not need to be heated, the LED lamp wastes much less heat and a lot of savings on the electricity bill. LED lights last a long time. Some models have more than 100,000 hours of life.
LEC – [Lamps CMH]
With increased lumens per watt emitted and improved yields and more natural light spectra, LEC lamps, also known as CMH lights, are attracting more and more attention from all world-class indoor cannabis growers. These are little-named lamps on the market but they are greatly admired by millions of growers.
LEC lamps work thanks to a ceramic discharge tube. What you get is a much more natural color, which produces more lumens per watt and lasts much, much longer. The advantages that this lamp offers are the color of the light produced, which is much more natural, in practice the natural color of the plant is much easier to observe, which is essential to check the health of the growing plants and if their these are problems that can be quickly recognized by their color variations. LEC lights emit UV-B rays, which enhance trichome production during the vegetative phase of cannabis plants. So there is a considerable increase in the final yields. Other advantages of LECs are their lifespan and easy connection without using external power supplies.
MH – [Metal halide lamps]
The light from MH lamps is generated by igniting an electric current from mercury gas mixed with mercury and a certain metal iodide. The light it produces falls within the ideal range of the color spectrum during the growing period of cannabis. Especially good for the vegetative phase. You can also use a 1000 watt metal halide lamp to induce the flowering period of the plant. After the introduction of HID lighting, growers in the United States have been using metal halide lamps for a long time and have achieved good results in all stages of plant growth.
HID – [High intensity lights]
HID lights were first invented on a large scale and used in public places and stadiums. This suggests that these types of light are very potent and, in addition to cannabis, many farmers also use them to grow many other things, but they are still very effective for cannabis. Among the various types of HID light, we find mercury, metal halide and sodium vapor.
CFL – [Fluorescent lights]
Growers have been using CFL lights to simulate the sun for many years for indoor growth and early germination in cold climates. Unfortunately, CFLs are expensive and require a large number of fluorescent lamps to simulate natural light.
Distance of the Lamps to grow cannabis
Here is a diagram containing the optimal distances that must exist between the lamps and the plants, depending on the lamp in your possession.
|Fluorescent light||(5-10 cm)|
|Lamps LED||(25-50 cm) |
[depends on the wattage]
|Lamps MH from 250 Watt||(20-30 cm)|
|Lamps MH 400 Watt||(30-40 cm)|
|Standard HPS 250 Watt||(20-30 cm)|
|HPS 400 Watt||(30-40 cm)|
|HPS 600 Watt||(50-60 cm)|
|HPS Agro light 400 Watt||(30-40 cm)|
|HPS Agro light 600 Watt||(50-60 cm)|
More suitable reflective materials
The first step in preventing light loss during the growing process is to get a light reflector. This means that you will need to place the light horizontally to maximize the reflection process.
The two most commonly used materials for reflectors are aluminum. Some growers recommend only painting the walls of the grow room white to reflect its interior space. But the best choice is the Mylar or Panda sheet. Only with these materials will you be able to reflect well the lamps to grow cannabis.