Best Indoor Grow Lights

Grow lights are one of the most important elements of an indoor garden. Whether you’re a seasoned hydroponic grower or just looking to extend the growing season, buying the right indoor grow light is essential.How to choose high quality plant lamps is also an important factor to promote the rapid production of plants.

In this article, we’ll dig into everything you need to know when it comes to choosing and using indoor grow lights.

I consider grow lights to be the #1 most important purchase when it comes to an indoor garden. Without them, everything else you need to grow indoors successfully is quite literally worthless.

Most people think that grow lights are only used in very specific situations, but they have a myriad of uses for gardeners of all kinds. Here are a few common ways indoor grow lights are used:

• ​To grow plants from start to finish in an indoor grow system
• To start seeds in preparation for the spring growing season
• To finish off plants that need a bit more sun than the season is providing
• To successfully propagate and root cuttings
• As a way to extend the daylight hours for plants grown in the sun
• To grow plants harvested at a young age, like baby greens, herbs, 

Because there are so many different reasons to use grow lights, there are a lot of things to consider when it comes to buying, using, and caring for a light. This article will get into just about everything you need to know when it comes to lights, with links to even more in-depth guides for specific topics.

* Note: This is a very long article. If you’re just looking for everything I’ve ever written on indoor grow lights, click ‘Additional Resources’ in the quick navigation.

Important Grow Light Concepts

Before we go any further, it’s helpful to understand a few basic concepts about lighting in general. By understanding these, you’ll be able to see what makes one grow light more suitable for a particular goal than another.
<h3″>Spectrum

All light — both visible and invisible — falls somewhere on a spectrum. This spectrum is measured in nanometers, which correspond to the wavelength of light. The particular band of the spectrum that we care about as indoor growers is the 400-700 nanometer range, also known as Photosynthetically Active Radiation, or PAR.

As the name suggests, PAR refers to the wavelengths of light that plants can actually use for all of the processes related to photosynthesis. Within this band of light, there are sub-sections that plants use for specific purposes:

• ​400-490 nanometers – This “blue” light is used by plants primarily during the vegetative growth phase
• 580-700 nanometers – This “orange-red” light is used by plants during the flowering and fruiting phase

You might be wondering, “What about the gap between 490nm and 580nm? Why don’t plants use that range?” Well…have you ever wondered why most plants are green? The choloroplasts in their cells absorb blue and red light, but reflect green light, which just so happens to be the color you see in the 510-570nm range!

Maintaining Your Grow Lights

Whatever type of grow light you’re using, it’s a good idea to follow a few best practices to make sure you’re getting the most out of you lights.

These concepts are simple and will allow you to get your money’s worth out of your investment in grow lights.​

Heat and Cooling

One byproduct of producing light is heat. Different grow lights have different levels of heat output. For instance, LEDs put out very little heat, while a 1000w HPS bulb puts out a lot.

When growing, you must take into consideration how much heat your light puts out and place them far enough away from your plants to avoid burning.

As a general rule, LEDs can be placed the closest to your plants, followed by fluorescents. HID and plasma lighting should be placed the furthest away.​

Bulb Degradation

All grow light bulbs degrade over time. Depending on the type, some degrade much quicker than others.

HID Bulb Degradation

HID bulbs degrade over time just like any other bulb, but the reason is different. Every time your turn on your HID lamp, the voltage pulses far above the level it operates at normally.

This pulse damages the bulb every single time you turn it on. After about 6-12 months, the properties of the bulb change enough that the spectral output of the bulb is significantly worse.​

T5 Fluorescent Bulb Degradation

Fluorescent lighting degrades much slower than HID lighting. There are a few reasons why this happens, but what you need to know is that they usually only lose about 10% of their lumen output after 20,000 hours.