Are LED Grow Lights Better Than HPS For Growing Marijuana Indoors?


When it comes to growing marijuana, there is no shortage of things that people argue about. The only thing that I think all growers can agree on is that other growers suck. I have grown cannabis during various times of my life, and plan on growing again soon. I took this indoor season off because life was just a bit too hectic, and I don’t grow outdoors because my backyard is not suitable for a number of reasons, not the least of which is that jackers can easily hop my fence and get to plants very easily.

But someday I will get back at it, perhaps next indoor season, and I am giving strong consideration to using LED grow lights. I have always used high-intensity discharge (HID) lamps when growing indoors, but LED grow lights have always intrigued me. I remember back in the 2000s when some of my friends tried them out. LED grow lights back then left a lot to be desired. Plants grown under LED grow lights in that era always reminded me of a sad, weak Charlie Brown Christmas tree. The harvested buds were really airy and whimpy, and the overall harvest was always really small.

Since that time LED grow lights seem to have come a long way. I know more and more growers that are incorporating them into their indoor gardens, especially commercial growers. Their harvested buds look just as good as what I see produced by by HID lamps, and the growers seem to be happy with their harvests. Of course, their happy social media posts are often quickly soured by HID growers throwing shade at them, but it leads to a zesty debate of the merits (or lack thereof) of each type of grow light. I always get the popcorn ready and read along specifically looking for the math involved.

What HID growers always point to is that they get larger harvests. They seem to concede that an LED grow light and a metal hallide (MH) light both work well for veg, but HID growers will tout how much more overall harvest they received using high pressure sodium (HPS) lights than people with the equivalent watts via LED-lit indoor gardens. I am willing to concede that in a straight head to head wattage match-up that the HID garden is going to outproduce the LED garden. LED companies will say that both put off the same intensity, but I have yet to see an LED garden beat out an HPS garden on yield when no other factors are considered.

But what LED growers have been pointing out at an increasing rate is that when a bunch of other factors are considered, and all the numbers are crushed, that dollar for dollar LED lights are the way to go. I have not personally grown via LED lights, so I will let others determine if that is fact or fiction, but I will say that the below list of thing should be considered in the ongoing debate of LED vs HPS.

LED grow lights put off less heat than HPS

According to LED grow light manufacturers their lights put off 90% less heat than HPS lights. This is one of the biggest selling points of LED lights. Anyone who has grown indoors in certain parts of the country during certain seasons knows that heat can be a major issue for a garden. Perhaps if you are an indoor grower in Alaska heat is not a concern, but I know that in my garage it gets very warm from the end of the spring through the summer. In the peak of the summer there’s simply no way to have a garden in my garage because it’s too hot, lights or no lights. That’s a big reason why I have been giving strong consideration to LED lights. They could give me a longer season, and cut back on AC requirements, which can be a huge energy hog and leads me to my next point.

LED grow lights consume less energy than HPS

Another big selling point for LED lights is that they use less electricity. The obvious counter argument to that is that more LED lights are required in order to match the output of HPS lights. I guess the devil is in the mathematical details on that one. With LED lights getting stronger per watt over time, this part of the debate is swinging more and more in LED lights’ favor. Some LED companies will swear that their lights can match the output of a 1000 watt HPS at a significantly reduced wattage, but whether or not that is actually true is always tough to say. After all, they are selling something.

But I do think that there may be some validity to the argument that, overall, the overall output of ‘X’ amount of LED wattage can match 1000 watts of HPS output, and that ‘X’ is less than 1000. When you combine the savings from the light energy usage itself AND the savings from not needing to run the AC as much (if at all), the argument in favor of LED becomes even stronger.

LED grow lights don’t require replacing expensive bulbs and have better warranties

A typical HPS bulb has a limited warranty for a year. The ballasts tend to have warranties of 3 years. Perhaps there are others with shorter and longer warranties, but those are the warranties I have seen on boxes at the grow stores in my area. An LED grow light does not need to have one big expensive bulb replaced after a year like an HPS light. Although, little LED grow lights may become defective to play devil’s advocate. But most of the LED lights I have seen out there carry a three year warranty on the LED bulbs themselves, and five year warranties on the ballasts and other parts of the light setup. That adds to the cost savings on the LED side.

To be fair though, LED lights tend to cost more than HPS lighting setups, at least the quality ones. Where the math ultimately falls is hotly debated, but I personally feel that over enough time the LED light is cheaper due to the energy savings from the light itself, the reduced AC costs, and lack of need to replace the HPS bulb each year or more.

LED lights are better for the environment

All of the previous points of discussion are based on quantifiable math. The specific math involved is case dependent due to the AC needs involved and how long an LED light properly performs before becoming defective. But whatever the case may be, the argument on the LED side is that when you compare an HPS harvest to an LED harvest, with the LED harvest costing less on energy and bulb replacements, that the LED harvest costs less gram for gram to produce than HPS over time. Also, that those savings take into consideration that LED light setups tend to cost more initially than HPS setups.

But one thing that is not really debatable is that LED lights are better for the environment than HPS lights due to the energy savings. Indoor cannabis cultivation has a huge carbon footprint, and reducing that footprint is invaluable. Whether or not that’s something that any particular grower is concerned with depends on the grower, but I definitely don’t want to use anymore energy to grow cannabis than I need to. I would prefer to grow cannabis outdoors, and hope to someday, but until then this is one of the biggest selling points to me personally on LED lights.


In summary, whether or not an LED grow light is better than an HPS one involves a lot of factors. The debate will likely rage on for years to come, with LED growers offering up math that shows they are right, and HPS growers offering up math that says they are right, and both sides claiming that the other one is fudging the numbers. With cannabis strains and environmental factors being varied across the world, it makes matters that much harder to pin down.

I tend to lean towards LED these days, but I am still not completely sold on the idea. What do Weed News readers think? Are LED lights better than HPS setups, or is it the other way around, and why? Have you used both types of lights, or are you just saying the other side sucks from afar? Be honest!

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