Want access to a world of information? Join our Cannabis Growers Club! Here you will be able to learn more about growing cannabis as well as get some great tips and tricks from fellow growers to take your growing skills to the next level. 

Take me to the Cannabis Growers Club of South Africa

What are Grow lights and why are they important?

A grow light is an artificial light source that has a specific light spectrum needed to help support the process of photosynthesis in plants. Photosynthesis is the chemical process in which light energy is converted within a plant to energy a plant can use to grow and produce. Plants use the blue and red light spectrums. Blue light on plants is directly related to chlorophyll production. Plants that receive plenty of blue light will develop, healthy stems and leaves. Red light is responsible for helping plants flower and produce fruit.

Grow Lights are an essential part of any indoor grow. The best type of light will always be the sun but when growing indoors you need a grow light that will provide the best quality and amount of light for your plants. The right amount of light is essential in a plants survival as a plant needs light in order to photosynthesise for survival and growth.

If you’re new to growing, the variety of different grow lights available can be overwhelming therefore it’s important to know what different types of grow lights there are so you can choose which is right for you.

Grow lights can be broken down into three main categories:

• High Intensity Discharge (HID)
• Fluorescent
• LED

HID (High Intensity Discharge)

High Intensity Discharge (HID) lamps are a top choice amongst indoor growers because of their reliability and very high light output. These HID grow lights produce a lot of heat and so they should there be kept fairly far from the plants. This technology consists of a lighting ballast, lamp reflector and HID bulb. Types of HID lights include Metal halide (MH), High Pressure Sodium (HPS), CMH (Ceramic Metal Halide) and Double ended bulbs.

          MH (Metal Halide)                HPS (High Pressure Sodium)         CMH (Ceramic Metal Halide)                    Double-ended (DE) 

     

MH (Metal halide) 

MH grow lights produce a white light which helps encourage lush, green leafy plant growth. These lights are generally used in the vegetative stage of growth when plants are young and growing just stems and leaves. MH lights can be used throughout the entire grow cycle however this is not advised. Used as the main source of light in your indoor grow will produce shorter more bushy sized plants.

HPS (High Pressure Sodium) 

HPS grow lights produce an amber light which promotes the stretching out of the plant and bud formation. These lights are great for the flowering stage. The amber light spectrum triggers hormones in the plants which increases bud formation in the plant. HPS bulbs can be used for the entire grow however plants grown using only HPS light will generally be too skinny and grow too quickly. Something to note with HPS lights is that they create a lot of heat. To control this heat, you would need air-conditioning or an exhaust system.

If you can only choose one light for your grow cycle, it is always recommended to go for the HPS bulb as these will do better for your entire grow. Growers often combine these two bulbs in the different stages of growth, using MH for the vegetative stage and then switching to HPS for the flowering stage. Some light fixtures provide a choice of using either MH or HPS lighting, but not at the same time. These lights are known as two-way, switchable or convertible lights and make it super easy to switch form MH bulbs to HPS bulbs in the flowering stage

CMH (Ceramic Metal Halide) 

CMH grow lights are like an evolved version of high-pressure discharge lights. These lights use a ceramic core instead of the traditional quartz metal halides use. The ceramic element of these light gives a higher intensity of light that can extremely closely mimic natural sunlight. These types of light contain different types of gas the HPS and MH lights. They also connect much better due to the different thread they come with. This makes these bulbs more secure. The CMH or LEC grow lights hardly create any heat because of the addition of insulation so your plants don’t burn, they also have more UV-A and UV-B in its spectrum, which is very beneficial if you are growing cannabis.

These grow lights are available in a variety of different light spectrums such as growth, flowering and mixed spectrums.

Double-ended (DE)

Double-ended grow lights are another type of HPS light that connects to each end of a ballast instead of just one ballast port. The DE light maintains about 90% efficiency, while a single-ended light loses efficiency after about 10 000 hours of use. The slim design of the DE light also helps provide more light.

 

Fluorescent

Fluorescent grow lights are generally the least expensive lights. They also use less energy and operate at a much cooler temperature compared to other grow lights. There are 2 main types of fluorescent grow lights, CFL (Compact fluorescent) and T5 fluorescent tubes. 

                  

    CFL (Compact fluorescent)                                      T5 fluorescent  

    

CFL (Compact fluorescent)

CFL grow lights are a good choice for smaller grow areas or novice growers as they do not require a ballast. They simply screw into a socket incorporated on a wing reflector. CFLs produce light in all directions so the purpose of the wing reflector is to capture and reflect the lights rays onto the plant. This ensures that no light is wasted.  CFL grow lights use less energy and produce significantly less heat compared to HID lights. The CFL bulbs are divided into half, one side is of the blue light spectrum which will be used for vegetative growth, and the other side is of the red light spectrum which will be used for flowering.

T5 fluorescent

T5 grow lights are similar to LEDs and CFLs in that they produce much less heat which means you can hang them much closer to your plants. This grow light also uses less energy and can simply be plugged directly into the wall, unlike the MH/HPS bulb, which requires a ballast and a reflector. With a lower wattage than high intensity systems, these fluorescent grow lights are perfect for germinating seeds, rooting clones and for the first few weeks of the growth period.

  

LED

                                         

LED (Light Emitting Diodes) grow lights are part of the newest light technology introduced to the world and have become an increasingly popular choose among indoor growers. LED lights have a low power consumption which means you can save a lot on electricity. They also give off a lot less heat compared to HID lights, this means you can place your lights much closer to the canopy without the fear of burning your leaves. Another great thing about growing with LED’s is that you are able to optimise their spectrum to output more of a certain light spectrum depending on which growth stage your plant is in.  

The main disadvantage of these lights has been their high cost however costs have been dropping as they continue to be produced in larger volumes by more manufacturers. These lights are also popular for their long life and efficiency which makes them a great long-term investment.

Shop Grow Lights Here