What type of lighting is used for growing cannabis indoors?

If you grow indoors, you need grow lights. But they can’t just be any lights. They must be capable of providing the type of light your crops need to boost healthy development and yield incredible flower.

You may have noticed that in recent years, the light-emitting diode (LED) has increased in popularity among growers. But you’ve likely also heard growers talk about bad experiences they’ve had with LED lights, recommending high intensity discharge (HID) lights instead. HPS grow lights have long been a go-to choice, and there is a lot of useful information on how to use them effectively.

So, What type of lighting is used for growing cannabis indoors?

HPS or LED: A Key Factor to Consider！

One of the reasons you still hear people claiming that LED is not ready for commercial cannabis grows is because the reflectors from an HPS fixture mounted 4 ft from the canopy will provide a wide angle of light so the crop will receive light from the fixture directly above as well as the lights from the next row over and even 2-3 rows away. This light is coming in from different angles hitting the crop beneath the canopy leaves that are causing shadows from the light above. This does not happen if you are using an LED fixture that is a big panel of LEDs or made up of multiple LED bars where they have to be mounted 9-12 inches from the canopy. You get no crossover from the fixtures but only shadowing from the top of the canopy.

It was only after companies like P.L. Light and Philips* introduced LED fixtures specifically engineered for truss mounting in a greenhouse, that growers really adopted this technology. These products enabled even the indoor grower to maintain some distance between the LED fixtures and the plant canopy, and resulted in production similar to growing under HPS. (*In the United States, Philips has taken the stance that they will not support sales into the cannabis industry as it is not recognized to be legal by the federal government)

Advantages of LEDs over HPS

  • Efficiency – LED diodes are very electrically efficient, which could save you money over time (though the jury is still out when it comes to whether LEDs get better yields than HPS watt-for-watt). Additionally, where an HPS bulb needs to be replaced every few grows to maintain its brightness, individual LED diodes keep their brightness practically forever. With an LED grow light, it’s almost certain something else will break on the lamp before any diodes start losing their brightness.

  • Plug-And-Play – LED grow lights are plug-and-play which means you can simply hang up the lamp over your plants and plug it directly into any standard electrical socket. HPS lighting requires the use of a ballast; for smaller models it can be built-in, but larger HPS lights generally need a brick-sized external ballast.

  • LED Grow Lights Come With Built-In Cooling – Along the lines of being totally plug-and-play, most LED lamps have heatsinks and small built-in fans to help disperse heat up and away from the lamp, which lets them run cooler. On the flip side, even a small HPS bulb needs extra help for cooling, usually by venting out hot air using a fan and ducting.

  • Customized Color Spectrum – It is known that the color spectrum of light affects how plants grow. Unlike other grow lights which are pretty set in their color spectrum, each LED diode can be configured to emit light of a very specific color spectrum chosen by the user. This means that LED grow light color spectrums can be adjusted and customized in a modular way that’s impossible to achieve with any other grow light. I trust that full spectrum LED grow light is best for plants growth

So, Are LED Lights The Best For Indoor Growing?

As you can tell, there are definitely some advantages to going with an LED system, but whether they’re the best choice for indoor growing depends on a few factors. For a lot of growers, the low temperature, efficiency, lifespan, size and spectrum of LEDs make them ideal for indoor grows. Undoubtedly, LED grow lights is the best grow lights for indoor plants. Other growers, typically those running large-scale operations, prefer HID lights because they provide the most intense light. Of course, HIDs come with their own challenges — they consume way more energy than LEDs, and also force the grower to invest in additional equipment, like protective hoods and exhaust fans. But if your main goal is to maximize the quantity of crops that your garden produces, then HID is probably the way to go.