7 Key features you should know about LED grow lights

Light is the most important variable in plant growth and development, and is usually the biggest limiting factor. Therefore, the use of plant growth lamps in commercial greenhouses is beneficial to both plants and growers. The reasons for using growth lamps vary, including increasing the light level of plant photosynthesis or changing the photoperiod. The duration of light perception by plants is photoperiod. Different light sources that growers can use include incandescent (Inc) lamps, tungsten halogen lamps, fluorescent lamps, and high intensity discharge (HID) lamps. Light emitting diode (LED) is the fourth generation of lighting source, which is a new technology in the field of horticulture.

Choosing the right grow lamp is the most important part of establishing the indoor system of hydroponic or organic garden. Even if there is no sunshine or weather conditions, the growth lamp can still provide the light energy needed by plants for photosynthesis.

The following are the important parameters of plant growth lamp;


Grow lamp spectrum refers to the electromagnetic wavelength of light produced by the light source to promote plant growth. For photosynthesis, plants use a light standard rod (photosynthetic effective radiation) wavelength range (400nm-700nm), including red, blue and green bands, measured in nanometers (nm). The growth of plants mainly depends on red and blue light. The earliest led growth lamps were based on the spectra of these two wavelengths. With the deepening of research, it is found that far red light is closely related to yield and the potential to control growth. Therefore, led plant growth lamp has been updated to targeted full spectrum growth lamp to improve production and quality

2. Photosynthetic photon flux (PPF)

PPF or photosynthetic photon flux is the total amount of light produced by the light source in the par region per second. Therefore, PPF measures “photosynthetically active photons emitted by the lighting system per second”. Expressed in micromol / s.

PPF describes the total amount of light emitted by the lamp. PPF measurement is carried out in a device called “integrating sphere”, which measures all photons generated by the fixture. However, even in an ideal setting, 10-15% of these photons will be lost due to radiation or reflection. Choose the right growth lamp according to your planting area and available PPF.

3. Photosynthetic photon flux density (PPFD)

PPFD describes the par photon density at a specific point (measurement location). There is a limit to the photon density that plants can use. The maximum photon density (PPFD) ultimately determines the maximum number of photons (PPF) we can provide in the growth space. This represents the photosynthetic photon flux density, which measures not only PPF, but also surface area. Therefore, please consider factors such as the distance from the light source, the number of measurements in the average value, and the minimum / maximum ratio before purchasing.

4. Wattage

This is the most common measure of growth lamp intensity, a measure of electricity (watt = ampere x volt). This determines the amount of power you actually consume. In fact, when choosing plant lamps, “the higher the power, the better the output” is inaccurate. In the case of emitting the same photon density, the smaller the power is, the less heat is emitted, and the higher the optical performance is. Misleading, you need to know the actual power consumption, not the LED wattage mark. At present, led plant growth lamps on the market can be dimmed. You can adjust the light brightness according to different stages to control the photon density and reduce your energy consumption.

5. Uniformity

Uniformity refers to the ability of the growth lamp to provide uniform light distribution on the plant canopy. The uniform light distribution provides a consistent light level for the plants in the whole canopy. Photosynthetic photon flux density (PPFD) and photobiological flux density (PBFD) can be used to measure uniformity. Completely uniform light will have a ratio of 1/1.

6. Light intensity

This relationship between the light intensity (output) and the distance from the light source is well understood as the physical law (called the inverse square law), and the light intensity of each growth lamp behaves the same. When comparing growth lamps, light intensity is one of the most important measurements to know. Although, more light intensity is only better to some extent. But too much light intensity can burn plant tissues, such as seedlings

7. LED chip quality

Well known manufacturers use complex technical processes to ensure that the diodes they produce emit the correct light wavelength and are highly durable electronic components. There are also inexpensive LEDs that may or may not emit the wavelengths required by our plants, and their emitted light intensity will change and / or decrease within weeks or months after use and after the diode heats up.

Leave a Reply

Protected with IP Blacklist CloudIP Blacklist Cloud