Common mistakes and misunderstandings to avoid when using LED grow lights for planting
LED grow lights are quickly beginning to dominate the industry. Once growers make changes, many people often forget to consider new factors. We will review some common mistakes to avoid when planting with LED grow lights.
The chandelier is too high
Many growers who switch to LED plant growth lights often hang the lights too high above the tree canopy. Although the typical installation height of HPS/CMH lamps may be 24-30 inches, this is an inappropriate installation height for LED grow lights. The LED grow light is designed to be installed 6-12 inches from the tree canopy to achieve maximum output. This proximity is possible because they generate much less heat than comparable HPS products. The evenly spaced diodes in our design allow for uniform light distribution over the growth area, even at these narrower mounting heights.
Since the target PPFD is lower, you can choose to install the lights higher during the plant growth phase, or if you are looking for a slightly more uniform light distribution, you can raise them a little bit. The higher the light installation during flowering, the less light will reach the plant due to absorption and light scattering in the air. The ideal way to use LED grow lights is to place them as close as possible to the canopy without burning the plants. In a well-ventilated area, we found that the installation height was close to 6 inches. If you do choose to hang the lamp above 12 inches, this will be at the expense of optical density and final yield.
Using incorrect spectrum
Before investing in any grow light, understanding the spectrum is crucial to knowing what is best for your plant. The growth lamp should provide the spectrum that can best drive the photosynthesis of plants. This can be done by copying natural sunlight, which is the light wavelength of the full spectrum. Although red and blue light are the most famous light that stimulates plant growth, they also use and require additional wavelengths of light, such as green and yellow, in the process of photosynthesis. In order to obtain a more comprehensive growth, it is important to obtain a full spectrum of light, which has all combinations of wavelengths and colors. The fact that green light is not easily absorbed by plant cells is actually beneficial to plants, because green light will not be absorbed by the oversaturated leaves at the top of the canopy, but can penetrate into the plant and pass the light to areas that would otherwise be ignored.
When LED plant growth was first introduced to the indoor gardening market, they only produced red and blue lights, known as "Smurfs" or "fuzzy" lights. Although these lights may still be able to do the job, their caliber is not as high as full-spectrum LED plant growth lights, and they will not produce high-yield or healthy plants. This gave the early LED grow lights a bad reputation. When switching to a full-spectrum LED plant growth lamp, it is important to obtain a lamp that has full-spectrum light and maximizes the growth of plants. LED grow lights provide full-spectrum light output.
Low quality LED
LED grow lights entered the indoor gardening market much later than HPS/CMH lights, and at first they could not compete with high light output. In recent years, the progress of LED plant growth lamps has produced extremely high output, which not only competes with HPS counterparts, but also exceeds. Unfortunately, many of these low-quality lamps still exist and fail to produce the high light output required to maximize plant growth and yield.
To ensure that you get high-quality lighting with good performance, it is important to check not only the wattage of the luminaire, but also the light output (PPF). Wattage only specifies how much power the lamp uses, but does not specify how much light output it actually produces for plants. This is the best way to evaluate lamp efficiency. Make sure that the light intensity is sufficient to produce an average PPFD of at least 500 µmol/m2/s during the vegetative phase, and at least 900 μmol/m2/s during the full cycle growth and flowering phase-but the higher the output, the better! Our 720W FL-1 full cycle LED plant growth light has one of the highest light output on the market, with a PPF of 2000 µmol/s, or our two 440W VL-1 full cycle LED plant growth lights together have incredible The high PPF of 2440 µmol/s.
Overwatering
When switching from HPS/CMH to LED grow lights, another common mistake is excessive watering. This is because HPS/CMH lamps are much hotter than LEDs when they operate, and they also produce more infrared light, which causes plants and soil to dry out faster. This results in watering procedures that are heavier and more frequent than those required under LED lights. When switching to LEDs, be sure to check your soil and monitor your plants before continuing the same watering procedure.
Common misunderstandings about LED plant growth lights
Since LED grow lights are relatively new to the indoor gardening industry, there are many misunderstandings that need to be recognized before evaluating or buying LED grow lights.
Color temperature
Many people use color temperature as the main factor when evaluating growth lights, only measuring the appearance of the light in the human eye—that is, whether the color temperature of white light is warmer or colder. Color temperature can hardly tell us the actual chromatographic distribution of light, which actually affects plant growth. The human eye cannot always accurately perceive this color spectrum, which is why light with the same Kelvin looks the same in color temperature and may have different spectral profiles, which will have different effects on plant growth. The most popular growth lamp used at the time was HPS or CMH, both of which were high intensity discharge (HID) lamps. These types of lamps produce light with a fixed spectrum because they all use the same gas in the lamps, so there is not much difference between lamps. This makes it possible to talk about color temperature in less precise terms. However, depending on the number and type of chips used, LED plant growth lights can produce almost any spectrum of any distribution.
The chromatogram of light is also very important, because each wavelength (color) of light is responsible for different aspects of plant growth. Blue light promotes stoutness, while red light helps plants stretch, while green light helps penetrate the plant canopy. Plants use all wavelengths of light for full growth, which is why it is best to obtain full spectrum light using all color combinations. Most high-end LED plant growth lights use full-spectrum white light, which is similar to the sunlight that evolves and grows plants. This is why color temperature is not the most accurate way to evaluate the spectrum of LED plant growth lamps. You should consider the specific spectral distribution of each lamp.
Wattage
When considering different plant growth lamps, many people will determine the intensity of the lamp based on the wattage. Wattage only specifies how much power the lamp uses, not how much light output it actually produces for the plants. Light output or PPF ultimately determines the effectiveness of light for plant growth. Using wattage to evaluate the PPF produced by growth lamps is another reserved point when HPS and CMH lamps become the standard. They have relatively fixed effects. This means that regardless of the brand, the 1000W DE HPS lamp will always produce a very similar amount of light. However, this is not the case with LED plant growth lights.
For LEDs, it is more important to consider the efficacy of specific light, that is, the efficiency with which light can convert power (wattage) into plant light. Efficacy varies with the quality of the LED plant growth lamp, which means that lamps with exactly the same wattage may have very different light output. For example, because LEDs are much more efficient than HID lights, our 720WLED grow lights have higher light output than ordinary 1000W DE HPS lights, while also using less energy. Even among LEDs, there is a big difference in efficacy. An example is how our 440WLED grow light has a light efficiency of 2.8 µmol/J, which can produce a higher PPF than HLG’s 480W grow light because its light efficiency is only 2.5 µmol/J. You want to look for high-performance lamps so that you can get the highest light output while using less electricity.
Calcium and magnesium deficiency
It is a rumor that LED causes calcium and magnesium deficiency, and it started when people started to notice purple stems when using LED lights instead of HPS. Although purple may be a sign of magnesium deficiency, if your plant does not have any other signs of distress, this color means that the plant is producing natural purple pigments (anthocyanins) in response to ultraviolet light. This is only true with high-quality full-spectrum lamps that produce ultraviolet light, and because many man-made HPS and LED lamps do not produce ultraviolet light, many growers are not familiar with this purple. Therefore, if there are no other signs of distress—such as yellow spotted leaves—purple stems are not necessarily a negative sign, but if you are using a high-quality lamp, it is a positive sign.
