Grow Light Color Temp

Last Updated on August 28, 2022 by Sam

Are you ready to learn about grow light color temp? Let’s get started. When it comes to indoor hydroponic gardening, one crucial aspect is the grow light color temperature. Grow light supplies your plants adequate light that mimics sunlight so they don’t miss out on utilization of the required light.

For your hydroponics plants to grow well, you need to get the accurate grow light color temperature for all your plant stages.

It might be quite confusing getting these light requirements. However, it is essential for all hydroponic growers to understand these light conditions. This is why we will be enlightening you on color temp, light spectrum pigments, their requirement for various plant stages, and more. So, read on to learn.

Color Spectrum

Let’s talk about the color spectrum of sunlight. In a standard situation, plants make use of sunlight. The colors we see sunlight produce is usually white light or yellowish-white light.

These white colors the sunlight produce are a mix of several colors of a rainbow and the mixture gives the white or yellowish-white colors. Therefore, the graphical display of all these colors of light is known as the color spectrum.

Sunlight Color Spectrum

Grow Light Color Temp

Plants develop and progress with their life cycle from seedlings, adult, flowering, and then to the fruiting phase. Therefore, different colors of light are required for all these stages of a plant’s life cycle.

The grow light color temp comes in different hues of spectrum required for your various plant growth stages.

The color temperature of any light source is the tones or colors of light seen to human eyes. We measure the bulb of some of these grow lights by color temp and color temperature is measured in degrees Kelvin.

Kelvin Scale Of Temperatures

Let’s take a look at the Kelvin scale which is expressed in color temp. It is used to express the appearance of different color temp. From the Kelvin scale, we can see the soft tones of the red light spectrum at the lower end. These red light tones are required for the life cycle of the plant’s flowering and fruiting phase.

Kelvin Scale Of Temperatures

There is the tone of the blue light spectrum on the other side of the Kelvin scale. The vegetative phase of a plant requires this light. Grow light such as HID and fluorescence makes use of this scale.

Grow Light Color Temp: HID & Fluorescence Grow Light

HID (high-pressure sodium and metal halide) are the traditional grow lights we know of. They are pretty different from LED grow light in that they don’t give out single colors the way LED lights to do.

For these HID and fluorescence grow light, the light they emit is usually yellowish soft hues. The grow light fluorescence bulb has its color temp as either cool white (which has more blue hues) or warm white (which has more red hues).

Grow Light Color Temp: LED

LED grow lights are one of the most accurate types of light. This is because they will supply you with the exact or accurate grow light color temp your plants need. LED grow light will offer your plant a full spectrum. This implies there’s no stress of changing the lights as your plant progress to their flowering and fruiting stages.

PARFACTWORKS RA1000w LED Grow Light Hydroponic Full Spectrum

An appropriate LED should possess these colors for all your plant life cycle in the right measurements: Red LEDs (600 to 700 nm), Blue LEDs (400 to 500 nm), some white LEDs, and some far Red LEDs (700 to 800 nm).

Light Colors Spectrum Pigment That Plant Use

Plants make use of light for the photosynthesis process and this is made possible by some chemicals or pigments present in the plant leaves. Examples of these pigments include Chlorophyll A and B, carotenoids, etc.

So, let’s take a look at what some of these pigments do with light:

  • Chlorophyll: plants are quite rich in chlorophyll. Chlorophyll is one crucial pigment that helps plants with photosynthesis. They assist plants to take in light energy turning them into plant energy for use.
  • Carotenoid: another abundant chemical or pigment found in plants is the carotenoid. It works hand in hand with chlorophyll. They help plants absorb light at the same time sending the energy back to chlorophyll. Carotenoid also serves as protection for chlorophyll from photodamage especially when the plant is predisposed to too much light required.


What is the best color temperature for grow lights?

The best color temperature for growing plants is between 4,000K and 5,500K. The range of light that a plant needs to survive is 4,000K to 8,000K. This range is called the "thermal optimum" range. Plants are much more sensitive to light than you might think. For example, if you move a plant from a low light setting to a bright, high light setting, it will usually not die, but it may have to adapt.

If you are unsure of what color temperature to use, just use the color temperature on a light that is as bright as you can get it. You do not need to worry about the color temperature. As long as the light you are using is in the thermal optimum range, your plants should be fine.

If you move a plant from a high light setting to a dimmer light setting, it can die. This is why we often see plants in florescent lights, which provide very little light, and grow more vigorously than they would if they were in regular fluorescent lights. If your plant is getting too much light, or is receiving no light at all, it will stop growing.

What kind of light source should I use?

LEDs are an excellent option for growing plants because they last longer than HID and CFLs. You can purchase LED bulbs in both high intensity and low intensity. Low intensity bulbs provide lower light output, but are more efficient.

High intensity bulbs provide higher light output, but are more expensive. The most important thing to consider is the number of watts you need. LEDs have a lifespan of 25,000 hours. This means that you can use them for 20 years or more if you use them sparingly. LED bulbs also have better heat dissipation. CFLs and HIDs have a lifespan of 1,000-2,000 hours. If you have a room with no ventilation, you may want to use HIDs or CFLs.

What does color temperature mean?

The color temperature (K) of a light bulb is the perceived color of the light as compared to the other colors in the spectrum.

For example, a 3000K light is orange/yellowish and will warm up the color of your plants. A 5500K light is more blue/purple and will cool the plant down. The difference between the two would be like going from a 4000K light bulb to a 2000K light bulb. The same goes for the grow tent, which is probably similar to having a 4000K grow light but without the ability to adjust it. You could also get a grow light with an adjustable color temperature and use it in conjunction with a grow tent that has an even higher color temperature.

Final Note

The plant life cycle will require the various color of light for different stages of the life cycle. All hydroponic gardeners need to know about grow light color so they can enjoy optimal production.

So, we do hope you have learned some things on grow light color temp.