Grow lights either replicate the sun’s light spectrum or provide a range that plants need the most to satisfy their photosynthetic needs and other light-related needs. Outdoor conditions such as temperature, solar intensity, etc. are replicated with alternating color, temperature, and spectral outputs from the grow light, in addition to varying the intensity of the lamps. The plants are exposed to different ranges of the spectrum along with luminous efficiency and color temperature depending on their growth stage, for example, germination or vegetative stage or flowering and fruiting stage. They all require different intensity and performed better under some specific range of the spectrum.
Although any light will spur the growing process of plants, not all lights will provide the best conditions. The same goes for artificial lights. Some artificial light may emit too much heat, which is not suitable for the plant, while some do not have the right spectrum of light for ideal growth. Blue light and red light promote plant growth and flowering, respectively. Therefore knowing the right frequency to use at the right time is essential. That is why a grow light that gives you a wide range of option is vital as the health and yield of your plant depends on it.
1) High-Intensity Discharge (HID) Lighting
HIDs are potent lighting systems. They are on the high side and are expensive to maintain. They can be fitted into rooms with little or no access to sunlight to grow plants that require light intensity ranging from low to medium.
High-intensity discharge lights work by utilizing tubes filled with gases. Electricity is passed through a tube or bulb that contains this mixture of gases; the result you get is an impressive beam of light. These lights are famous for their role in stimulating exceptional growth in plants, herbs, and vegetables. Some of their significant advantages are the fact that they emit twice the light a traditional fluorescent light will produce, and they last longer when compared to others. However, they do not come cheap as they are relatively expensive. These lights can go as far as serving as the only primary source of light for plants. That is how powerful and efficient they can be.
The blue light of Metal-Halide (MH) lights, which is a type of HID light, will enhance vegetative growth, but flowering plants may not fare better.
Here are the types of HID lights:
High-Pressure-Sodium (HPS) Lighting
High-pressure sodium (HPS) lights are designed to replicate the kind of lighting that is produced inside a greenhouse. It usually used in areas of the world that receive a little amount of sunlight. These lights emit large amounts of heat; therefore, it is crucial to have advanced cooling systems installed in the areas where the light source is being utilized. Also, the plants should be closely monitored because some plant pests are attracted to infrared rays, and the HPS light produces such kind of radiation. The bulbs of the HPS emit warmer colors of the color spectrum, such as reds and orange. These are suitable for flowering plants and producing buds. However, the plants might become less sturdy.
Although High-Intensity Discharge solutions like Metal Halide and High-Pressure Sodium lights are excellent choices, they are expensive to operate.
Metal-Halide (MH) Lighting
The type of light emitted by Metal halide bulbs mimics the kind of sunlight that we get around the transition of spring to the early months of summer. It only uses a fair amount of power and is a relatively new source of lighting.
It is also possible to combine Metal halide lighting with HPS lighting. This, in turn, leads to high-quality plant growth. As a result of this combination, a unique bulb is created. It is known as a dual arc bulb and can serve throughout the entire lifespan of a plant.
Unlike HPS bulbs, MH bulbs emit cool white coupled with blue, and they fall on the cooler side of the spectrum. MH lights are suitable for enhancing plant growth.
MH and HPS lights can be used simultaneously. The former can be used to enhance the leafy growth before switching to the latter, which is then used to strengthen flowering plants.
Both types of HID light available have high intensity. However, installing them is a different ball game. They both require their separate ballasts.
HPS systems use igniters, while MH systems do not use igniters. This feature prevents you from switching an HPS bulb with an MH bulb. It further means that you can use either MH or HPS, but not both at the same time. Nonetheless, it is quite possible to have both HPS and MH lamps on a ballast, but it is an expensive venture.
2) Fluorescent Lighting
Fluorescent lights are widely used by home growers, and the reasons are solid. Unlike the older fluorescent bulbs which lack adequate range, newer types of fluorescent bulbs offer a wide range of the light spectrum. This makes them suitable for all-round use. The traditional fluorescent bulbs are ideal for plant germination and vegetative growth. Some of the reasons why this type of lighting is popular are the fact that they produce lesser heat compared to their counterparts. They are safer, versatile, and can prove to be more effective than incandescent bulbs. They are also budget-friendly.
Fluorescent lights are best suited for plants that require low or medium light intensity, for example, the African violets. They are also ideal for when you plant vegetables indoors. These lights generally come in long, tube-like bulbs, and they have different sizes, which are the T5, T8, and T12.
The smaller the surface area of a fluorescent bulb, the more effective and radiant. Also, compared to incandescent light, they use seventy-five percent less energy. So, a regular 25-watt fluorescent will shine as bright as a 100-watt incandescent bulb. A tube of the T5 fluorescent systems will emit twice the amount of light a standard fluorescent light will produce. It has a temperature of 6500 Kelvin and provides a full spectrum of intense light.
3) Induction Lighting
They are similar to fluorescent lights. However, their differences arise when you ask how light is produced in their separate tubes. They come up instantly, and with the same intensity. Light is produced as a result of the interaction of gases in the tube and an electromagnetic field. Therefore, it is not advisable to use this type of light at home as it will likely interfere with your home Wi-fi and alter the cell service.
They are designed for industrial use; you can tell this from their strength. Induction lights can last for an extensive number of hours and are ideal for commercial farming operations. However, they can be noisy.
4) LED Lighting
Light Emitting Diode (LED) lighting is arguably the least expensive lighting system you can find for indoor grow lights in terms of running cost. According to reports from suppliers, operating cost is reduced by approximately 60 percent or more.
The demand for LED grows lights is increasing. So are the suppliers as different brands are entering into the business. This has also led to the production of below standard grow lights. Therefore, it is advisable to stick with older brands or brands with a good track record. These brands put a lot into research and rolling out better products. Although these products might be more expensive, however, it should be a worthy investment.
The required range of wavelength that is suitable for plant growth falls between 300 nanometers(nm) to 700 nanometers. Blue light can be found around 300nm and slightly above while the upper part of the scale tends towards red. The blue light is ideal for growth, while the red light is suitable for flowering plants. LED lights fall within the wavelength of 660nm to 460nm. With the former providing red light similar to those received by outdoor plants during peak time sunlight in summer while the latter delivers blue light.
Also, it essential to monitor the LED system for heat. Although the bulbs do not generate much heat, the other parts of the system can, however, increase in temperature. Therefore, it is best if you get one that has cooling fans installed in them.
5) Halogen lighting
Halogen lights are not the ideal grow lights for your indoor plant. Apart from the fact that they only emit red light, its running cost is not the most efficient, and it is also quite expensive.
Since they only emit red light, then they are only suitable for flowering plants and not for plant growth.
Therefore, if you are using this lighting system, you will need a source of blue light, which can either be LED or fluorescent.
6) Incandescent Lights
Incandescent lights are usually used to give plants supplementary lighting after they have received sunlight or light from other indoor grow lighting systems. They are not perfect or ideal for grow lights; however, some can perform well.
They have a short lifespan and are known for generating an excessive amount of heat than illumination. They consume too much power and have a high running cost. It is not easy to control their temperature, and they should not be kept too close to the plants so as not to burn the leaves.
Their production is slowing gradually as the world is now delving into newer, sustainable, and energy-efficient sources of lighting.