How Does an Indoor Grow Light Work?

As simple as it may sound – just shining a light on a plant – the world of grow lights is a dense online jungle to navigate for someone just starting out seeding.

LED lights often have blue and red, and sometimes purple, often referred to as “blurple” when it’s all three. A warmer tone will be a lower kelvin, and a cooler tone will be higher. If you’re planning on growing veggies, a full spectrum light with a color temperature in the blue range (5,000 – 7,000K) is recommended, and for fruits and flowers, the red range (3,500 – 4,500K) is the guiding light. These tones boost growth and absorption more than others, but for photosynthesis, plants really still need the full color spectrum if possible.

A leaf’s chlorophyl absorbs the red and blue light extremely well, but can block that light from penetrating further into the plant below and preventing deeper growth beneath the leaf’s structural surface. White LEDs fuel growth in the mid-spectrum, bringing out the deep greens in a leaf, but often slacking on the sides of the spectrum, leaving out cool blues and intense infrareds.

Aren’t they all full-spectrum LED grow lights?

No. They are labeled as such, but they are not actually full-spectrum.

Most contain LED diodes in multiple colors.

That means they have specific wavelengths, but not every wavelength. The wavelengths between the diodes the light contains are missing.

There is only one way to get a true full-spectrum output.

That is with white light.

I will explain why and also which combination of diodes gives you the best light for plants (hint: only white is not as effective as white plus additional diodes).

I will also show why LEDs and CMH bulbs are the only two cost effective ways to get the ideal full-spectrum white light.

And I will show you exactly which LED fixtures provide this ideal light and do so at a reasonable cost. Why spend over a thousand dollars on a light, when you can get the same thing for a few hundred?