Why Do You Need Grow Lights [Not Regular Lights]
What is The difference between Grow lights and regular lights
Grow lights are designed to give plants more red and blue light for photosynthesis. Regular lights have only blue and yellow and almost no red. Grow lights also offer higher PPFD and wattage. Thus, grow lights are more effective and efficient than regular lights for growing plants. However, both lights can grow plants if the regular light is a full spectrum.
You think grow lights are expensive, but do you know why?
For some people, growing lights is a must. This includes countries where sunlight is scarce, cities where growing space is scarce, and people who want to grow food everywhere, from their basements to their bedrooms.
But pretty much every one of them thinks this question. What’s the difference between a grow light and a regular light? Why can’t they use the regular one to grow plants?
Well, you definitely can. But you shouldn’t—for a good few reasons. That’s what we discuss in this post.
Prime differences between a grow light and a regular light.
If you’re reading this, I assume you already know what a grow light is. It’s an artificial light we use to grow plants. It can either replace sunlight or complement it. When we say regular light, we refer to the lights we use in our rooms.
These two types of lights have at least five key differences (besides cost). Here are they.
Grow lights produce more red and blue than yellow.
Plants need light for photosynthesis. It’s the process of transforming water and carbon dioxide into glucose.
White light contains all the colors—blue, yellow, red, and everything. But plants don’t use all these colors equally. They use red and blue lights more and a lot less yellow. Not that yellow is not needed but in small intensity.
With more blue light, plants become healthier and more vegetative, with larger and thicker foliage. The red range helps plants with reproductive needs such as flowering and fruiting.
But the room lights we have aren’t white. They are either more yellow or yellow and blue. Yellow and blue together looks a lot like white but more pleasant.
This lack of red and excess yellow is the prime difference between grow lights and regular lights.
But blue light isn’t the same between the two types of light, either. Plants do need some UVA light. One study has found that supplemental UVA-radiation exposure for 12 h/d was more conducive to plant growth. But, since excess blue light can cause sleep disorders in humans, it is relatively low in regular lights.
Grow lights are more intense than regular lights.
Regular lights are very bright. Isn’t this enough to grow plants? Indeed, it isn’t enough.
Bright doesn’t mean they are intense. Brightness is often measured in lumens and lux. However, light intensity in agronomy is measured with PPFD.
PPFD stands for Photosynthetic Photon Flux Density. PPFD refers to the number of photons within the photosynthetically active radiation (PAR) range (400-700 nm) that strike a square meter of area each second.
Although regular lights are brighter, their PPDF is significantly lower than grow lights.
Grow lights are more powerful.
Let’s compare LED room lights with LED grow lights to keep the comparison fair. Some grow lights, such as HPS, are far less energy efficient than LED ones.
Most regular lights don’t exceed 60W—these are the giant ones. Why should they use more energy if they could produce enough light to brighten the whole room?
But grow lights need more power.
Grow lights often come in 100W, 200W, 400W, etc. Of course, they consume more energy. But they produce more intense light optimized for plant growth (more red and blue)
Grow lights can cool themselves; regular lights don’t Need Cooling.
We now know that grow lights are more powerful. Although most of this energy goes into producing light, a hard-to-avoid side-effect is the heat. Powerful lights produce more heat.
Also, regular lights don’t have to keep lighting the space for more extended hours—except for industrial cases. But grow lights have to. For instance, most seedlings need at least 14-16 hours of light.
For these two reasons, grow lights must find a way to release their heat. Yet, this is rarely a problem for regular lights.
Most grow lights come with integrated cooling systems. They have heat sinks and fans to keep them cool for longer.
Grow light can Last longer.
Yes, grow lights can live longer than regular lights.
Regular LED lights are expected to last about 25k hours, but grow lights can last up to 100k. There is a stark difference between the two.
Doesn’t this alone justify the premium cost of grow lights?
Related: A Manufacturer’s Guide To Growing Plants With Lights.
When can I use regular light as a grow light?
After all this time, here’s a section discussing using regular light as a grow light.
We know that regular light lacks red, and even its blue range doesn’t have the UV-A needed for plant growth. However, in three scenarios, you can still use regular lights to grow plants.
But what if you need light only to supplement sunlight?
This is still true in many parts of the world. People don’t get enough sunlight, but they do get some. In such cases, you can use a regular light, such as a T5 tube or any LED light, as a grow light.
But you have to accept the drawbacks. Don’t expect the flowering plants to produce flowers. They won’t. Also, it’s never going to be the optimal use of electricity.
Another use case is to provide light to plants that grow in the shade, such as succulents, cacti, and houseplants. These plants don’t need much light; they naturally grow with a bit of light coming from a window. So, they should do well under regular lights, too.
The third case concerns seedlings and microgreens. Seedlings use a lot more blue-green light than red, and high light intensity may kill them. Thus, you may use regular lights for seedlings and microgreens.
But if you try to grow crops like lettuce in a completely dark environment like your basement, you need to grow light. The regular lights don’t have
Make sure the light is full-spectrum. Even though the plants in these exceptional cases are okay with a partial spectrum, they may still need some of every part of the white light.
How about grow light as regular light?
This is clearly not necessary and not recommended.
The high intensity of grow light may brighten your room, but the extra doze is a hazard to you in many ways. Although grow lights are generally safe, they aren’t good enough for room lights.
The intense light coming from the light could damage your eyes. It may initially cause eye strain. But eventually, you’re running into the risk of developing cataracts and fast aging.
Further, the extra blue light in the grow light will cause sleep disorders. Although the UV-A range is considered safe, you still run into the risk of developing skin cancer.
This is why professional growers who can’t avoid prolonged exposure to grow lights wear lab coats and grow room glasses. This is why they aren’t good for your living room or bedroom.
Related: Are Grow Lights Safe for Humans?
Final thoughts
At first, the difference between growing and regular lights seems narrow. But they are very different.
If you’re serious about growing with lights, you should invest in a grow light. Hobbyists may start with a regular LED light; this could work to an extent. Yet, only an LED grow light can help you grow better plants.
Yes, they are costly. But for serious growing, they are a must. A longer expected lifespan justifies the cost.
