Overview of led plant light types: choose the right light

Posted on Aug 22 , 2020

If growers, gardeners or just amateur growers do not have the opportunity to grow their favorite flowers or plants in the outdoor garden, or do not have time to find a place suitable for outdoor growth, then there is another way to be relatively easy and stay at home.

This is the so-called closed cultivation, which is also indoor cultivation. This is an artificial imitation of nature and its natural behavior. But there is a big difference. In nature, growers are restricted by various external factors, such as bad weather, wild animals, thieves and enviable neighbors. They have always been interested in the mysterious plants growing behind the fence. In the home environment, do not take measures that may damage plants. Growers have the opportunity to test their skills and artificially stimulate growth conditions to create more beautiful and productive plants.

The main prerequisite for starting planting is the amount of sunlight required. This radiation can be simulated by artificial lighting, which produces a spectrum similar to the sun. Under artificial lighting, growers can determine the maximum spectral range of plants in a specific period of time.

Three kinds of lighting are suitable for the growth and flowering of plants: high-pressure lamps, fluorescent lamps, LED and plasma lamps.

Without light, plants would not exist, because light is one of the main factors in its development. Light is an important energy source for photosynthesis.

Photosynthesis is a combination of these processes-the absorption, conversion and utilization of light energy through various reactions involving the conversion of carbon dioxide into organic compounds. In other words, this is the process of forming organic compounds based on carbon dioxide, water, heat and light, energy.

To choose the right lighting, you need to be familiar with all types of lighting.

High intensity discharge lamps (HID) are classified according to the burner and the gas it contains:

Mercury discharge lamp (MV / mercury vapor lamp).


The mercury discharge lamp was the first gas discharge lamp developed in 1959. Mercury lamps mainly emit blue and ultraviolet light in the invisible spectrum. The luminous flux of these lamps is low (approximately 65 lm/W). Compared with metal halide lamps and sodium lamps (approximately 150 lm/W), this light is considered weak for crop production.

Metal halide lamp (MH/metal halide lamp).


The first MH lamps were developed in the early 1960s. The metal halide lamp is characterized by a "white" light color, which at first glance is different from, for example, a sodium lamp. Metal halide lamps have a blue spectrum with a color temperature of 6,000 K or higher. The blue spectrum has a positive effect on the root system of plants, resulting in better branches and shorter internodes. The plants under this lamp are lower but have branches. However, during the flowering period, this lamp is usually not suitable.

Metal halide lamps are very suitable for cuttings and seedlings. Small plants don't like light, they branch well from the beginning. It is also recommended to use this type of lamp on the mother plant to ensure more buds and faster plant growth.

The burner in the lamp is shaped like a bulb. The flask is filled with a mixture of mercury, argon and metal halides (for example, metal compounds and bromine or iodine).

These lamps have wattages of 150 W, 250 W, 400 W, 600 W, 1000 W and a color temperature of 4000 K.

HPS/High Pressure Sodium Lamp.


Sodium lamps were put on the market in the early 1970s and are the most widely used type of lighting for plant growth in the world. This is mainly because they have the highest luminous efficiency (approximately 150 lm/W) and also emit FAR radiation that is most suitable for correct photosynthesis. The light emitted by the HPS lamp is mainly in the red spectrum, which is suitable for the flowering period of the plant. The color temperature of the lamp ranges from approximately 2000 K to 2900 K and produces bright yellow.

The sodium lamp burner is mainly made of corundum.

Sodium lamps are available in 70W, 150W, 250W, 400W, 600W, 750W and 1000W, and can be used in the growing period, provided that the plant has more internodes and tends to extend toward the light.

The advantages of HID lamps over other light sources are indeed very high. These lights are used for indoor planting and large greenhouses for commercial planting. Disadvantages include higher operating temperature.

The second light source most suitable for growing plants is linear and compact fluorescent lamps, sometimes called resource-saving, energy-saving, compact fluorescent lamps, etc.

These lamps have a great advantage in that they do not emit heat like HPS and MH lamps. Therefore, they can be grown in a small space near the top of the plant without worrying about burns.

The use of fluorescent lamps does not only depend on micro growth. Producers use them to illuminate the mother plants, rooted cuttings and seedlings. But this is not all. Due to their color temperature changes, these lamps can be used in all stages of plant life.

Fluorescent lamps are low-pressure mercury lamps, which are divided into compact and linear types.

Fluorescent lights.

These lamps have been widely used since the early days of indoor growth.

Fluorescent lamps are called fluorescent lamps, and their glass tubes are made of glass and filled with a mixture of mercury and argon. In these lamps, the luminous discharge emits radiation mainly in the ultraviolet part of the spectrum. This radiation is caused by the phosphor in the tube and produces light in the visible spectrum. The two ends of the fluorescent tube are electrodes that conduct current.

Growth fluorescent lamps are usually available at 18 watts, 36 watts and 54 watts, and are 60 or 120 cm long.

Compact fluorescent lamp (CFL-compact fluorescent lamp).

If a manufacturer is looking for a compact fluorescent lamp with sufficient wattage and the correct color temperature in a traditional hardware store, the search may be futile. However, this shortcoming has recently been solved by producing more durable compact fluorescent lamps that are not only suitable for growth but also preferred by a group of manufacturers. The bulb is filled with a small amount of mercury and inert gas and can only be purchased from specialized stores.

Compact fluorescent lamps are available in the following color temperatures:

  • 2700 K-red spectrum, suitable for flowering period.

  • 4000 K-double spectrum for growth and flowering.

  • 6400 K-blue spectrum, suitable for growth period.

  • 14000 K-white spectrum, suitable for rooting of cuttings, seedlings and female parents.

It should be noted that when combined compact fluorescent lamps are used, the results will be lower and the plant life span from planting to harvest will increase. Therefore, it is recommended to use blue spectrum lights and red spectrum lights.

CFL lamps that can grow are currently available in the market at prices of 125W, 200W, and 250W.

Compared with linear fluorescent lamps, CFL lamps need to be replaced more frequently. According to the usage time, the guaranteed working time is about one year. Then, the intensity of these lights will drop quickly.

LED lighting also occupies its due position in the market, but for some LEDs, it represents the future of evolving technology, while for some people, its expectations are too high.

The recognition that LED lighting (light emitting diode) can be used for plant cultivation is now very widespread. However, only a few people know the advantages and disadvantages of this LED option.

LED is an electronic semiconductor device that emits light when current is directed.

Mankind became familiar with the first type of LED in 1962, and since then, this type of lighting has been continuously developed.

Currently, the brightness of LEDs is 100 lumens per watt, which is sufficient for farming. The LED structure is an LED chip (or a combination of chips) coated with epoxy resin with required optical properties. Some manufacturers also use the optical properties of lenses to enhance the intensity of light concentrated in one place. The most common power LEDs installed in the panel are 1 watt and 3 watts, and 6W LEDs can be used in some countries/regions.

Compared with HID lamps, LED panels have an interesting function. They do not emit heat radiation, which is a huge advantage for manufacturers who often suffer from high temperatures. In addition, the total power consumption of the lamp is less.

LEDs are completely different from other light sources because there is no tungsten wire that will burn or fall over time, and there is no gaseous component, which makes the lamp more durable. In addition, since the main component of the LED (diode) is hidden under the epoxy layer, it becomes an indestructible component. Opinions on LED lifetime vary widely. However, in general, the running time is approximately 50,000 hours.

The advantage of LED panels is the combination of diodes with different chromatographic spectra, so this kind of lighting is suitable for all stages of the life of the factory. The LED backlight panel has excellent depth. Perhaps because of the above lens, the panel can be hung on the plant and can better illuminate the buds (depending on the type and wattage of the panel).

However, this kind of lighting has its disadvantages, such as high cost, which prevents gardeners from buying LED panels. Many manufacturers like to try and experiment with new technologies, but because of the high price, they must think twice before buying such products.

Since LED panels are manufactured in various shapes (circular, square, rectangular), they only emit light at a specific angle, so it is difficult to expose the entire growth area.

Given the constantly evolving technology, one of the biggest innovations is LEP (Light Emitting Plasma).

LEP is also called plasma, sulfur lamp, sulfur lamp, etc. Some manufacturers also call this lamp PLS (Plasma Lighting System). Although the terminology is different, this is the same product, based on microwaves and sulfur.

Plasma is the biggest innovation in the ever-growing lighting technology and was launched on the market in 1990. Unfortunately, in the same year, due to a commercial failure, these lights were discontinued and later put on the market again.

The FAR range produced by this lighting system is very wide (good for plants), close to the solar spectrum. Imitating solar radiation is almost the original intention of all LEP manufacturers.

The color temperature of the LEP plasma lamp is about 5600 K, which indicates that it is intended for the growth phase. The manufacturer recommends using this light for the growth period, and it is worth using HPS after the flowering period. If you choose to feed the plants with plasma light during flowering, you should be prepared for low yield but highest quality. When using LEP as the lighting for the mother plant and cuttings, excellent results can be obtained.

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