LED Grow Light Distance Chart: How Far Should LED Grow Lights Be From Plants?

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Providing your marijuana plants with high-quality lighting is one of the best ways to guarantee that you get bigger and better yields. Lighting matters a lot – when your plants are growing in the natural sunlight, they get that light from the sun, which is always at a fixed distance away from them at any given point in time. However, when you grow your plants indoors you basically substitute the sunlight with indoor LED lighting which you can adjust nearer or further from the plant based on the need of the phase of growth it is in. 

In this article we shall specifically be closing a detailed look at how far LED grow lights should be from the plants to provide them the best possible growth without harming them. We shall also be providing you with a comprehensive distance chart which will help you understand which phase of growth requires what kind of lighting. However, before we jump on to all of that, we will quickly go through what LED lights are and what their benefits are – as well as what kind of lighting is needed during different phases of the marijuana growth cycle. Several other questions related to this topic will also be answered!

What are LED Grow Lights and Why Are They Important for Growing Marijuana?

LED grow lights are the latest kinds of grow lights that are being used to grow indoor plants. They are particularly useful for growers who are cultivating cannabis indoors. Plants, when growing naturally under the skies, are in a constant need of light – which comes to them via the natural light of the sun. When growing indoors, these plants generally do not have an access to sunlight and hence require grow lights. 

There are a number of different types of grow lights such as High-Intensity Discharge lights and Fluorescent lights, but LED grow lights are the latest and the most modern form of lighting systems these days – here are some benefits of these grow lights which make them the hot favorite among modern-day growers:

Benefits of LED Grow Lights 

First things first, LED grow lights consume very little power compared to practically any other type of lighting. These lights consume half to a third of what an HPS grow light would consume and make a lot of economic sense even though the initial cost of purchase is a little higher in comparison to most other lighting solutions. In addition to that, LED grow lights are also important for another reason – as they offer you a full-spectrum lighting option without having to change the lighting setup.

In case of older lighting solutions, you would need to change the light between one phase of growth and another to meet the needs of the plant. In LED grow lights, you can do that by just pressing the switches! LED grow lights are also beneficial for growers as they are easier to dispose and do not carry any toxic chemicals. These kinds of lights also tend to last for a much longer time (more than 100,000 hours) compared to older grow lights. LED grow lights also emit a lot less heat and are safer to use as they do not burn the plants.

Growth Phases of the Marijuana Plant and Lighting

Now that you know what LED grow lights are and why they are important for growing weed,  here’s a look at the different stages in the cannabis plant’s growth cycle along with a description of the kind of lighting they require during this phase. A more detailed description is provided in the next section where we have shared a LED grow light distance chart which will give you exact measurements. 

While there are seven stages in the journey from seed to harvest, we have excluded the seed, germination and harvest stages as these phases don’t really need lighting. Light is needed in the pre-vegetative (seedling) phase, the growth (vegetative) phase, the pre-flowering phase, and the flowering phase of the marijuana plant. Here’s a detailed insight into these four stages:

  • Pre Vegetative Phase

In the pre-vegetative phase, plants need lots of lighting – this is essentially the seedling stage where about 20 to 22 hours of lighting can be provided to the plants. Plants need the cool blue lighting during this phase. 

  • Vegetative Phase

This is the next stage in the marijuana plant’s growth cycle where the plant progresses from being a seedling to being a full-blown plant with quite a bit of foliage. This is a phase of rapid growth and this is where the plant undergoes a lot of physical changes. Plants need about 18 to 20 hours of cool blue lighting during this phase.

  • Pre Flowering Phase

Pre flowering stages require about 14 to 16 hours of lighting and a fair mix of red and blue lights. This is where little buds begin to emerge. 

  • Flowering Phase

The final full-blown flowering phase requires a lot of red light and the lights also need to move closer to the plants than they were in the vegetative phase. In this phase, you need to provide only between 10 to 12 hours of light to the marijuana plant.

The distance is determined by the wattage which we shall look at up next: 

LED Grow Light Distance Chart: How Far Should LED Grow Lights Be From Plants 

Knowing what kind of lighting is important but it is also quite critical to know how far your lights should be from your plants. Here’s an LED grow light distance chart which will help you understand how far you should be keeping your lights from your plants. However, the wattage of your lights needs to be kept in mind before adjusting the height. The higher the wattage the further distance should be. Here’s a quick chart that will help you understand it:

  • If your wattage is 200W, you should keep your lights about 12-20” away from your plants during the vegetative phase and about 8-12” away during the flowering phase. 
  • For anything between 250-400W, it should ideally be 16-30” away from the top of your plant during the vegetative phase and about 16 to 18 inches away during the flowering phase.
  • For growers who use a grow light of 550 to 650W, it should be 24 to 30 inches during the first half of your plant’s growth and about 16 to 18 inches during the flowering season. 
  • If your cannabis plant is growing with a 600-800W LED grow light, you need to hang it about 32 to 36 inches above your plant in the vegetative phase but lower it to 16 to 20 inches during the flowering phase. 
  • For a 900-1000W LED grow light, the distance from the top of the cannabis plant during the vegetative phase should be 36 to 42 inches while the distance during the flowering phase should be 18 to 24 inches. 
  • Growers using a 1200W LED light for growing cannabis indoors should hang the light 30 to 36 inches from the plant’s top during vegetative phase but lower it to 18 to 24 inches when flowers begin to bloom. 
  • A 1500W LED light would require the growers to hang it about 30 to 36 inches above the plant in the vegetative phase while they will then need to lower it down to 24 to 30 inches during the flowering phase.
  • For a super-bright 2000W LED grow light, a distance of about 26 to 30 inches is appropriate during the vegetative phase of the marijuana plant while a distance of about 24 inches would be ideal for the flowering phase. 

Basically, the brighter your lights go and the higher the wattage, the higher you need to hang them from your plant else you might risk your plants suffering from what is commonly known as ‘light burn’ where portions (especially on the top of your plants and flowers) tend to turn black and look burnt due to excess lighting. 

Top 3 Best LED Grow Lights in 2020

With everything about LED grow lights now known to you in brief, here’s a quick look at the five best options you have when it comes to buying a great LED grow light for your marijuana plants in 2020:

1. Advanced Platinum Series P450 450w 12-band LED Grow Light

  • Power Draw: 137w Veg / 255w Bloom
  • Dimensions: 11x19x3 inches
  • Warranty: 5-year warranty, 90-day money-back guarantee

PlatinumLED is among the best and the most trusted names in the world of marijuana growers. The brand is known for its high-quality lighting solutions. This particular model from them is the P450, which ensures the growers get bright 450W output while consuming only 255W of power at the most. This is a 12-band full-spectrum light which the manufacturer claims is 2 to 3 times brighter than most other grow lights. Having a full spectrum lighting ensures that both phases of the plant’s life cycle are covered without having to change the setup.

There are separate veg and bloom mode switches which make things easier for growers. You also get the assurance of an American company using high quality LED lights. This light can easily replace a 600W HPS light and offers you with a 4.5ft x 4ft coverage from 18”. This is a grow light which offers you with an incredible 5 years of warranty – the longest in the industry! 

2. Spider Farmer SF1000 LED Grow Light Dimmable

  • Power Draw: 100.5W±5%@AC12 0V
  • Dimensions:  11.8 x 10.5 x 2.3 inches
  • Warranty: 3-year warranty

Spider farmer is another of the best names in the markets these days which makes grow lights that will help your plants grow bigger and faster. Their use of LM301B Diodes makes them a great grow light as these Samsung LEDs are bound to last longer than what most of their competitors offer. This grow light covers an area of 3×3 ft during the vegetative phase and a coverage area of 2×2 ft during the flowering phase. This is also a dimmable grow light, which means you can easily customize the intensity of the light. 

The Spider Farmer SF1000 is a full-spectrum LED grow light where you can get a perfect combination of the reds as well as the blues. This is a modern-day board-design LED light which means there are no bulky panels and noisy fans and heat is dissipated with the help of heat sinks. This grow light also supports daisy chaining allowing you to connect one grow light to another instead of having to connect all of them separately with the power outlets. You also get uniform light coverage with these grow lights. There’s a three year warranty that you get on this light.

3. VIVOSUN 2020 Latest VS1000 LED Grow Light with Samsung Diodes

  • Power Draw: 100W
  • Dimensions: 13.7 x 13.18 x 3.42 inches
  • Warranty: 3 years

Vivosun is among the most popular grow light makers in the world! The company makes products which are efficient and long-lasting, as well as trusted by millions. This is their latest design, a 2020 model of a quantum board LED grow light which is lightweight and does away with all the unneeded bulk, while also providing relief from the buzzing noise of the fans by eliminating them altogether! There’s a full-spectrum lighting arrangement on this grow light which gives a sun-like lighting experience to the plants helping them grow faster and stronger. These lights are dimmable as well, allowing you to create the perfect conditions for your plants.

The VS1000 from Vivosun also consumes only 100W of electricity, giving you the best power draw to output ratio. This is a 2020 model, giving you the latest tech benefits. The grow light covers 4×4 ft during the vegetative phase and about 3×3 during the flowering/blooming phase. The light is so bright that you get a pair of protective sunglasses to wear while working with this light which comes bundled with the package. Finally, you also get a three-year warranty with this grow light from Vivosun.

Frequently Asked Questions (FAQs) About Grow Lights

Here are the answers to some of the most common and frequently asked questions that we are often asked about indoor cannabis lighting and LED grow lights:

1. What if I don’t turn off the lights at all?

Overexposing your plants to grow lights would mean that you are giving them no time to rest and are overworking them. This would stress out the plants and you would eventually see some portions drooping or dying off. Another basic understanding is that in the lit hours plants generate food while they distribute it to all their parts during the unlit hours.

2. What are other non-LED lighting options?

Apart from LED lights, there are High-Pressure Sodium grow lights and Metal Halides which need to be changed based on the lighting condition you want. Similarly, you also have fluorescent lighting options which are pretty good but need to be changed based on warm and cool lighting needs. 

3. Are LED grow lights legal to grow marijuana?

LED grow lights are completely legal to use. However, growing cannabis using them might not be completely legal based on your local laws. Make sure you are confirming everything with your local law authorities before you start growing weed else you might end up in legal trouble!

Conclusion

We hope that this article gives you a three-sixty degree insight into the world of LED grow lights and helps you understand as to how to use them in the correct manner. LED lights are the best options that we have when it comes to growing marijuana plants indoors but they need to be used in a correct and precise manner in order to get the most out of your plants else you might end up damaging them or getting lesser yield than what you potentially could. We hope that our LED grow light distance chart helps you understand the lighting systems better. Do let us know in the comments or drop us a mail if there are any more questions! Till then… 

…Happy Growing! 🙂