Lighting During Indoor Cannabis Cultivation

How Can We Illuminate Our Cannabis Growing Area?

When setting up indoor cannabis cultivation, there are many factors to consider in order to achieve the best possible results. Among these factors, the choice of the type of lighting and the power of the latter are among the most important.

Depending on the type of light used, there are various advantages and disadvantages, which can lead to numerous errors during the cultivation of cannabis . Some types of bulbs have a higher efficiency (lumens x watt), but on the other hand they are a source of heat that can cause problems for many growers, especially those who grow cannabis in small areas or In particularly hot areas .

On the contrary, other types of lighting do not emit almost any heat, but the high price of some of these devices or their low efficiency compared to other lighting systems make them less popular in indoor crops. These types of lighting remain however interesting for people who can only get crops with light bulbs producing little heat.

The choice of lighting for indoor cultivation depends mainly on the condition of the plant. Depending on its life cycle, the plant prefers a particular spectrum and / or power (rooting / seedling, growth and flowering). Of course, the available space also influences this decision, some lightings emit too much heat to be used in reduced culture areas, such as HPS or MH bulbs.

Light Spectrum Adapted To Cannabis

About the spectrum of lighting, cannabis plants need mainly blue light (450-500nm) during the stage of growth and red light (610-750nm) during flowering.

During root rooting and seedling growth, most growers use simple fluorescent tubes or blue CFL bulbs . In a culture space of sufficient size, it is also possible to use MH bulbs which possess the same blue / white spectrum suitable for growth, but with a higher power than CFL. In this way the plant becomes stronger and stronger, thus preparing for abundant flowering.

Lighting with a red spectrum is used for flowering plants. Red is the color that best replicates the outside natural spectrum during the fall months, when marihuana flowers bloom naturally. The HPS lamps are used the most, followed by LED systems that offer good results, a lower power consumption and low heat emission, which is the main drawback of the high pressure sodium systems (HPS).

On the contrary, green light and cannabis do not conflict because it does not affect plants, so it is the spectrum used by growers who wish to work in the growing area when the lights are extinguished without Causing stress to blooming plants.

Illumination Systems For Cannabis

Fluorescent and CFL

This is the ideal type of lighting for rooting cuttings or for young seedlings. The low power required, the low power consumption and the low heat emitted make it an excellent option during these steps. There are conventional lighting systems with fluorescent tubes, or low CFL (Compact fluorescent light) bulbs, which are also fluorescent tubes but bulb shaped, with the typical lampholder on the reflector. CFLs have a built-in ballast, so you just have to connect them to the reflector and connect it to the mains to make the system work. Normally, fluorescents offer a power of between 18 and 55W per tube, while CFLs are only available in 100, 125, 200 or 250W (also available with a red spectrum for flowering).

Do not hesitate to read our article on the cultivation of cannabis with CFL lamps in order to know everything about this type of lighting.

Metal Halide or MH Lamps

If an explosive growth of plants during the vegetative phase is desired, MH bulbs are the best option. Their spectrum is perfect for this stage and we can find MH bulbs with a power superior to fluorescent and other CFL. This type of bulb needs a ballast to operate, compatible with both the MH bulbs and the HPS (High Pressure Sodium) bulbs, which are generally used during flowering.If the same ballast is used for growth and flowering, the watts must be taken into account, using, for example, bulbs and ballasts of the same power. These bulbs are usually available in 250, 400 or 600W.

These ampoules also offer excellent results during the stretch period of early flowering (first 2-3 weeks of flowering), they limit the stretching of the plants compared to a HPS, and create a more compact structure , Ideal for abundant flowering.

High pressure sodium or HPS vapor bulbs

This is the queen of flowering rooms, although in recent years the LED panels have gained ground. We can find HPS bulbs specifically designed for flowering, or of mixed bulbs (dual spectrum), used both in growth and flowering. It is generally accepted that this is the type of lighting that offers the most interesting final output. Its main disadvantage however lies in the production of heat emitted once in operation. The spectrum is also not expected for satisfactory growth. To reduce the heat emitted, some growers use cooltube reflectors , reflectors cooled by air, which, when connected to an extractor, reduce the environmental temperature by a few degrees. In general, HPS bulbs are available in 250, 400, 600 and 1000w. The 250W bulbs are suitable for a 60 x 60 cm or 80 x 80 cm growing space, 400W bulbs for a 100 x 100 cm space, and 600W bulbs for about 120 x 120 cm.

Our next article on SOG culture technique will give you more guidance on how to make plants bloom with an LED bulb according to