What are LED Grow Lights and Where do I Start?

2020-05-25

What are LED Grow Lights?

A: LED grow lights are specialized LEDs with a full spectrum designed to aid in photosynthesis an allow plants to grow with little or no sunlight.

Light Emitting Diode (LED) grow lights are ideal for all types of indoor grows and for supplemental lighting for outdoor and greenhouse grows. Opposed to regular lights, they do not require gas to operate within a bulb, but are limited to a small diode of light. LED lights last longer than standard incandescent bulbs or HID bulbs like metal halide and high pressure sodium (HPS), due to the fact that they have no filament, meaning they are not susceptible to burning out. This also helps over the lifetime of an LED lamp with less maintenance and repair costs such as replacing bulbs as you would with old lighting technologies. Where an HPS or metal halide bulb may last up to 20,000 hours, most modern LED chips are now rated at 100,000 hours, 5 times the life of older technologies. LEDs also hold their brightness much longer. An HID lamp can lose half it's brightness by the time it is halfway through it's life. A DLC Premium rated LED light will hold 90% or greater of it's lumen output for 36,000 hours, long after that HID lamp has burnt out. Another benefit to LED Grow Lights vs HID grow lights is the higher efficiency ratings.  LED lights do not create nearly as much heat, which in turn lowers overall electricity consumption costs while still offering a powerful lighting option. This brings about another huge advantage of LEDs in horticulture lighting, the savings due to not needing expensive cooling systems and the electricity those systems use to keep grow areas from overheating and destroying crops. LED technology is able to closely replicate light coming from the sun, offering solutions for the indoor growing of all types of plants. LED technology from innovative companies like CREE continues to advance and current LED horticulture chips are designed with full spectrum lighting covering a wide variety of light wavelengths, making them ideal for growing at any stage in a plants life. It's time to get rid of those old HID lamps and step into the future of horticulture lighting with LED full spectrum lights.

What do you need to consider when buying Grow lights?

Plants transform CO2 into sugar to fuel their life; literally, light is the source of life in plants. When the light is not sufficient, they can even change the locations, angles and shapes of their leaves, among other things. Somehow, plants seem to be able to recognize when they are shaded by the foliage of neighboring plants versus that of the shade from a rocks, buildings, etc., but how do they do it?

Plants recognize the shades of neighboring plants by sensing the ratio between red and far red light using specific light sensors called the phytochrome. In the shades formed by the foliage of neighboring plants, the ratio of red over far red light increases because red light is mostly absorbed by chlorophyll whereas far red light is reflected by leaves. When the ratio of red over far red light increases, phytochrome change their structure from Pr to Pfr, which leads to shade avoidance responses including stem elongation via increase of auxin concentrations in plant cells.

Plants also sense the seasonal change in light intensity, the length of daytime, temperature, etc. and decide when to germinate, when to grow and when to bloom. Daily and seasonal change in plants are cued by changes in the quality and quantity of sunlight and orchestrated by the biological clock in plants. Perilla plants were reported to produce only 6% of seeds when grown next to street lights. It is because the biological clock of plants was disturbed by the artificial light overnight. Making sure you plants not only get the proper spectrum of light but also the proper amount of it, not just in brightness but also in the amount of time a pant gets light is very important for the different stages of growth. This is often why even outdoor growers and greenhouses use supplemental lighting. As the hours of sunlight from the sun changes not only through different seasons but at different latitudes on Earth. With the addition of supplemental lighting, growers are able to simulate the amount of light a plant receives in different seasons. This allows growers to grow plants not native to certain latitudes and also to grow crops in all different stages of growth at anytime of the year. These are the tricks that are helping grow just about any type of plant in any area of the world. This is very important to food production in areas with temperate zones that previously were unable to grow crops necessary to feed the locals.

What is PAR?

A: Photosynthetic Active Radiation (PAR) is a measurement of the intensity of light shining on a plant. PAR is measured in photons, a particle of light, and ranges from 400-700 nanometers which is the visible spectrum of light. Higher and more complete PAR will result in better growing results.

What spectrum does PAR measure

A: Photosynthetic Active Radiation (PAR) measures 400-720nm, commonly known as the visible spectrum

Par Value

Photosynthetic Active Radiation (PAR) is a measurement given to LED lights that is simply the intensity of light shining on a plant. PAR is measured in photons, a particle of light, and ideally ranges from 400-700 nanometers. PAR is also a measurement of the light in the color spectrum that is able to be used by plants. Plants use these photons to turn carbon dioxide and water from the air into glucose and oxygen, in turn making the plant grow. The action of turning this carbon dioxide and water into glucose and oxygen is known as photosynthesis. LED full spectrum lights offer an ideal range of photons for plants that are most suitable for plants to undergo photosynthesis.

Kelvin 

Kelvin is the measure of color temperature and is extremely important when selecting what type of lights you will need. Kelvin is the color of light emitted in reference to a temperature. The color of light is important because under different colors, some plants grow differently. A kelvin of 2700 is most closely associated with everyday lighting that we would see in our homes, while typical daylight is near 6500k.

What light spectrum can plants use for photosynthesis

A: photosynthesis commonly occurs between 350nm to 780nm wavelengths.

Photons for Energy

Photons are particles of light that carry energy from lights. In the case of LEDs, photons are important because they come in different colors. For LED lights, the color of photons being emitted is crucial, as plants take in photon colors differently, allowing them to grow better or worse depending on the color. Using blue light photons, plants are able to tell what time of day it is, as well as where the source of light is coming from. This allows for plants to grow more efficiently, as they grow upward as opposed to outward. Red lights, although higher in intensity, plays a crucial role in the flowering process of plants. Too much red light however can lead to plants that are not ideal in shape, making them worthless to consumers.

Red lights typically range between 600-700 nanometers on the electromagnetic scale. This is higher range than blue light, which occurs between 400-500 nanometers on the electromagnetic scale. Using a mix of both blue and red lights, the colors that plants best use in the process of photosynthesis, is crucial to healthy yields. With LED technologies, lights can be manually controlled to adjust for an adequate mix of both these wavelengths of light. This is why full spectrum LEDs have become so popular in horticulture lighting.

 

Grow Cycle

 Because LED lights can be adjusted to different colors which affect the grow cycle differently, they are the ideal choice for all types of indoor grows. As plants grow, they must first establish a root system that will support the eventual flowering process. When in this stage, referred to as the bloom stage, plants are in need of more red lighting. As they progress out of the bloom stage, into the flowering stage, LED lights can be adjusted to change from mostly red lighting into a bluer based light plan.

This adjustment makes plants grow to their best potential, while maximizing potential profits. Once plants are ready to harvest, a lower level of blue lighting is required. In some instances, growers will turn LED lights off completely to let plants actively adjust to a natural state of night.

What kelvin is best for vegetation stage of cannabis?

A: 4000K in the vegetation stage

What kelvin is best for flowering stage of cannabis?

A: 2700K in the flowering stage

Although their is still much controversy over what temperature to use in different stages, the general consensus is to stick with cooler color temperatures like 4000K in the vegetation stage and warmer colors like 2700K in the flowering stage. Full spectrum lights can take the guesswork out of the job, offering great end results with the same light for any stage and are becoming the most popular choice for many growers.

CRI and R9 for Better Colors

What grow light spectrum is best cannabis?

A: Cannabis are a complex leafy plant and thus require a full spectrum LED from 400nm to 720nm

 

The Color Rendering Index (CRI) is a scale that shows how well an object appears under certain levels of lights. CRI is measured with 15 different possible outcomes, with R9 being the most sought after when it comes to horticulture lighting. When using LEDs for growing plants, R9 is extremely important as it is the accuracy of producing strong red colors in a light source. Make sure to look for this when buying any type of horticulture lighitng. Using LED lights allows for optimal CRI ranges that can not be reached with conventional lighting.

Cannabis Needs vs Needs of Other Plants

There are many differences to consider when comparing cannabis plants to other plants commonly grown indoors. For starters, cannabis plants require much more light than other commonly grown plants. The growth needs of cannabis in regard to light are significantly more important than other plants because cannabis plants are not resilient to change of temperature and seasons like other plants. Due to this, lighting must remain consistent for cannabis plants which is why electric lighting with indoor grows is extremely popular for cannabis. Other differences in growing needs for cannabis grow lights vs other plants is the amount of water needed, and climate. Cannabis plants require a significant amount more water than many other plants.

LED Lighting for Grow and Horticulture Compared to Traditional LED Fixtures

LEDs have become the go to choice for growing due to their high efficiency and spectrum control.   Grow lights will run a bit higher per watt than other LED Luminares but you are getting a high CRI at 93+ for grow lights compared to 70-85 for most LEDs.  That full spectrum high CRI (and R9) give the grow lights the stronger space in the 600-800nm red and green area.  Due to the higher color scores expect to see a 120 lumens to watt instead of the 140lm/watt found on others.  The Grow lights will typically have more aluminum or other heat reduction factors.  Where the LM70 is above 90,000 and LM90 is above 36000 on other LEDs that number will be closer to 50K-90K for grow light LM70.  

How many lights will I need?

What is the coverage area of lights and how do I plan it out?  Probably the most common question we get for grow lights.  The ideal amount of light for growth of different types of plants is below:

Cannabis is 7150 lumens (65 watts) per 2 square foot.

Vegetables =  4400 lumens (40 watts) per 2 square foot.

Plants =  2750 lumens (25 watts) per 2 square foot.

For this reason, the first step in factoring how many lights you will need is to determine your grow space. Once you have determined your grow space and the amount of plants you intend to grow, you can figure how many lights you will need to cover the entire area. The amount of lighting you will need per square foot is also dependent on the type of plants you intend to grow, as some plants require more or less lighting.

The other factor to keep in mind is how high to install the lights. Some basic standards to keep in mind are below:

 

For lights under 300 watts, start at a height of 18-24".

For lights over 300 watts, start with a height of 24-36".

Most growers will lower the their lights over the lifecycle of the plant bringing them closer to the plant in the flowering stages.

The higher the power of the light, the higher the light needs to be over the plant. Using an adjustable cable or chain to hang grow lights is always a smart idea so you can easily adjust the height as a plant grows. This also allows you to easily make adjustments based on signs the plant gives off to let you know if you need to raise or lower the light to find that perfect height.

AntLux's 4ft LED grow lights will provide high performance, long-lasting and energy saving for general purpose use. This plant growing lamp uses 50 watts, which is equivalent to 300w traditional lights. Our led plant grow Lights will cultivate record breaking growth, both in speed and quality.