Proper Grow Light Distance For Plants + Distance Chart

The majority of people that has an indoor garden chooses LED lights for their tent. They are very convenient because other than heat and light exposure, another very important feature is that LED lights have a lot of colors in their spectrum. However, many plant lovers wonder what is the proper grow light distance for plants.

The answer to this question depends on many factors, but generally speaking, the ideal distance would be 40-66cm for LED lights with low power, 50-75cm for those with medium power and around one meter for the LED lights that have more than 900W of power.

LED Lights

A lot of people, including myself, prefer LED lights for their grow tents. They don’t emit too much heat as the HID lights, so they won’t overheat your plants and cook them.

Even though they are a bit pricey and you need to invest more money in the beginning, they will save you a lot of cash in the long run. They consume less energy, so your bills will be low, and since they don’t produce too much warmth, you’ll be able to water your plants less often since there won’t be a lot of evaporation.
Also, when talking about evaporation, with LED lights, you can go with only one ventilation opening even in bigger tents because the air inside the tent won’t suffocate you as much as with HID lights.

However, even if they don’t heat up too much, they can still damage your plants if installed too close to them. That’ why it is important to know how far should LED grow lights be from plants or for how long to keep the light on the plants, in order to create the perfect conditions for their growth.

How Far Should Led Grow Lights Be from Plants

As said, the distance between grow lights and plants should be modified according to the plants’ needs, as well as the lights’ intensity. You should also be careful when choosing the crops for your tent because all of the conditions need to be perfect for all the plants you have inside.

What I like to do is choose the plants with similar requirements of light exposure and keep them in the tent together. In this way, I’m sure that neither one of the plants is overly exposed to grow lights, and vice versa.

When I decide which crops to grow together, I determine the best light intensity with the adjustable LED lights I use, and then I know how far should LED grow lights be from plants and I can change the distance between them. A good trick is to hold a hand under the light for a few seconds and see if it’s too strong or not.

1. Low intensity LED lights

If you use LED lights that have 200-400W of power, it’s recommended to keep them from 30 to 66 centimetres from your plants at the beginning, and from 20 to 53 centimetres when they’re blooming. This will give the plants enough light to create all the energy they need and grow the best they can.

2. Medium intensity LED lights

When it comes to the LED lights with 600-800 watts intensity, the best distance would be from 60 to 100 centimetres when in the vegetative state, and from 45 to 86 centimetres when blooming. The majority of indoor plants requires this intensity, so there’s a big chance that this is going to be the most common distance.

3. High intensity LED lights

If you own LED lights that have 1000 watts and more, the ideal space between them and your plants would be from 91 to 116 centimetres (and more) and from 53 to 91 centimetres when the plants are blooming.

Since the intensity is very high, you will want to be very careful and really make sure that the grow lights aren’t too close to your seeds and plants since that could damage them a lot.

Grow Light Distance Chart

The most important thing to consider when determining the distance is how powerful your LED lights are.

In that regard, if your LED lights are of 1000+ wattage, it goes without saying that you’ll have to position them a bit further away than those of 200-400 wattage.

Here is an in-depth chart for proper LED grow light distance that you should always keep in mind!

WattageThe Distance (inches)
1000 +36 – 46
800 – 100032 – 42
600 – 80030 – 38
400 – 60020 – 27
200 – 40012 – 20

Why Is The Distance Between Grow Lights And Plants Important?

If you’re an experienced gardener, you know that all plants are different. As I have mentioned many times in my posts, all of the plants require different conditions to grow and flourish, whether we talk about water, soil, warmth or light exposure.

That’s why it is important to choose the light intensity that will work well for the plant you want to grow. There usually isn’t any general rule about the power of the light that should be in your tent. That’s why today we have a lot of adjustable grow lights that can be modified in order to be usable with many different kinds of plants.

Some plants will prefer a grow light with less intensity but for a longer time, while some plants thrive if the intensity is bigger and the period of the light exposure shorter. Do good research before you start your collection of indoor plants and you’ll know how far should LED grow lights be from the plants you’ve chosen. Then adjust the lights according to that.

The importance of the space between lights and plants comes from there – if you have strong grow lights, you will want to hang them a bit further than the weaker lights because if they’re too close, they could easily damage your plants and even kill them if you don’t notice it on time.

On the other hand, if the distance is too big for the grow lights that aren’t very powerful, that can create difficulties when it comes to your plants’ growth and blooming because they won’t have enough light to produce energy that they’re going to consume to grow.

How to Notice If the Distance and the Intensity Are Wrong?

It took me some time to figure out why some of my plants weren’t growing right. If you’re a beginner and you aren’t able to grow some plants, don’t worry, it happens to everyone in the beginning! All you need is patience and some research.

If you notice small yellow marks on the leaves of your plants, this means that the grow light is too close to the plants, or that the intensity is too strong. In this case, you can either increase the distance or adjust the intensity, whatever is more convenient for your equipment.

If the light is too far or too weak, you will notice that some plants aren’t growing or blooming as much as they should, or maybe at all. If this is the case with your plants, increase the light intensity, or try keeping lights closer to the plants.

Don’t Forget to Clean the Grow Lights!

The grow lights will get dirty no matter the distance. This happens because of insects, dust, evaporation and the fertilizers you use in the watering solution. If you don’t clean your grow lights regularly, all of that will create a layer of insulation on the surface.

This will create more warmth than it should, and you risk losing your beloved plants since they could die because of too much warmth. That’s why it’s important to carefully remove the layer of dirt and keep the lights clean.

What is your experience with LED lights? Do you use them and on which plants? Share your experience with us.