Plants need light to thrive because this is the energy that they use to synthesize nutrients. Cannabis plants thrive under optimum light conditions whether they are growing indoors or outdoors. Outdoors they have to be exposed to 8-9hrs of natural light in a day. Indoors cultivation aims at mimicking the outdoor conditions; this is where artificial grow lights come in. This is not to suggest that cannabis plants need light throughout their cycle, quite the contrary. During the vegetative stage, the plants will use chlorophyll to attract light and use it to manufacture nutrients. As they move to the flowering stage, the chlorophyll will begin to breakdown and the plants will need both light and dark to allow the buds to fully mature and blossom.
Artificial grow lights can be an expensive affair, especially when you have large canopies. Cheaper options for lighting include incandescent and fluorescent bulbs. When used effectively, they can guarantee high yields while still maintaining a low cost.
What Are Fluorescent Lamps
Fluorescent lights are tubes that are filled with mercury vapor compressed to low pressure, usually, they are coated with phosphor powder which uses fluorescence to offer visible light. Electricity flows through electrodes in the tube which keeps the light burning. Fluorescent lamps are used to light up homes and they are easy to use.
Incandescent bulbs may be cheaper to install, but they consume a lot of electricity making them more expensive in the long run. Fluorescent bulbs also emit minimal warmth with the light, creating optimal temperatures for the plants. The light emitted is red and blue wavelength and they are essential for the vegetative growth of the plants. Together, they speed up the rate of photosynthesis.
Fluorescent lamps consume less electricity compared to modern grow lights such as HID lamps (High-Intensity Discharge Lamps). For home grows, this works well because they are cheap to install. However, HID lamps may be suitable for large scale growers because light from fluorescent lamps may not be able to penetrate dense canopies.
How To Set Up Fluorescent Grow Lights
Setting up fluorescent grow light is straight forward; it can be pretty easy if you have used these tubes at home. You will need 15 to 20 Watts per square foot, which is low intensity for indoor grows.
- Find a suitable place to do your indoor cannabis farming. It should be a space that is well aerated and free of damp and mold. A place with some natural light streaming light would be ideal.
- Once you have obtained good quality bulbs sufficient for your space, you can call in an electrician to mount them.
- Make sure there is sufficient space between the bulbs and the plants at their maximum height. The bulb should be 10cm-15cm above the plants; you also want to encourage the plant to grow horizontally and not vertically reaching for the light.
It will take between 8-12 weeks from seed to harvest, depending on the strain and seed type.
Fluorescent Light Types
Fluorescent lights come in two varieties; CFL lamps and T5.
- CFL Grow Lights
Most home growers have at least tried CFL grow lights, this is because they are cheap and easily accessible from local hardware stores. CFL has a cylindrical appearance with a twisted shape. They are ideal when you are growing a few plants like 6 or less. You have to place the bulbs close to the plants because they do not emit a lot of light. They can be used to light narrow spaces for marijuana plants.
- T5 Grow Lights
TF lights are the advanced version of CFL lamps. They resemble normal fluorescent tubes but they extend through a panel. The tubes can be extended by some inches towards the marijuana plant for efficiency. Unfortunately, they are not as efficient as Light Emitting Diode (LED) lamps and High-Intensity Discharge lamps and cannot be used for commercial grows.
SCROG – Screen of Green Technique
Fluorescent bulbs do not provide a lot of light, and the light may not get to covered regions of the plant. Some people have tried to bring the lamps extremely close to the plants, but this may be counterproductive because the lamps emit heat as well. The trick is to get a sweet spot where you can tap into all the advantages of these economical bulbs while making them deliver efficiently. The screen of green techniques can help you achieve this.
SCROG is a trellising technique that helps to spread out the light to all the parts of the plant that need light. A screen (or net) is spread either horizontally or vertically above the canopy and plants are leveled against this horizontal or vertical plane. When the plants are at the same level, light can easily penetrate to different parts of the plants.
SCROG is useful for small scale cannabis cultivation, it doesn’t work well for large scale cannabis cultivation.
Pros of Using Fluorescent Lights
- Cheap
- Easy to set up
- Convenient since it requires a small space and little expertise
Cons of Using Fluorescent Lights
- Cannot be used for large-scale commercial grow
- The yield is usually lower
Fluorescent lamps are convenient and cheap to use. They have a few drawbacks, but employing SCROG can help to optimize the benefits and make the venture worthwhile for the small scale cannabis grower.
References
