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Why Are LED Grow Lights Best?

LED Grow Lights are the Best Choice

MaryJane Farmer (think Betty Crocker and add Weed) gives indoor growers the advice that LED Grow Lights are best for almost all readers of this site.  A lot of other advice on the Web will tell you very confidently, that LED grow lights just aren’t as bright and intense as High-Intensity Discharge (HID) lights. And you know what, a lot of that advice was right… At the time it was written!

But LED technology has advanced rapidly—and continues to advance rapidly. So fast that often you’ll find the results on Google have not kept up! Old, outdated articles still litter the first few pages…

Google Is Not Always the Best Answer

Today, if you Google the question of What’s the best grow light technology for growing weed indoors? (and, yep, we have answered that before and we are doing it again!), you’ll likely see a confusing mix of highly conflicting opinions in the results.

Why? Because, broadly speaking, that’s the way Google’s algorithm is designed . … not to be confusing—but to deliver a mix of newer, fresh content alongside authoritative, older sites that lots of other sites have linked to. (Depending on the kind of query.)

For a lot of search queries that mix is ideal. One of those results will almost certainly be exactly what you wanted.

But when it comes to a field where one technology is long-established and only improves incrementally, while the alternative is relatively new and constantly improving… and questions about which of those two is best…

Well, that mix can make it pretty hard to find the right, most up-to-date answer.  MaryJane Farmer thinks the most up-to-date answer can be found on this site and specifically in two reviews of the best LED Grow Lights that have been recently updated for late 2021 and include lights for every budget.

Older articles continue to rank well long after crucial information in them, and the conclusions drawn from it, have ceased to be accurate. And then new articles often get based on them too. But in our reviews, we are updating regularly to give you information that is as current as we can make it.  And we are confident that LED Grow Lights are the best choice for indoor growers.

It’s Hard To Know Which Result To Trust…

If you look at the first couple of pages of Google for the topic of this article:  The most authoritative-seeming articles in the results are often a couple of years old, or even much older. LED grow lights have advanced massively since then.

So, to counter that, we look to the newer articles in the results instead…

However, many of those turn out to be based largely on the information in the older, “page 1” articles we just rejected.

Then still other articles in the results don’t have any dates attached at all… Who knows how current they are?  And finally, some are from grow light manufacturers, so may or may not be biased.

Full Disclosure

Or they’re from sites like ours, which clearly favors LED grow lights and earns a small commission from Amazon if you use some of our links—but don’t worry, at no extra cost to you when you buy. (Again, you could worry about bias—but bear with us here!)

So who can you trust?  In short: Yourself. Research everything thoroughly!

However, for the reasons we’ve already discussed, that’s no easy task.  So the aim of this article and this entire site is to sift through the chaos and give you a few reliable, up-to-date sources, save you some research time and bring you a whole lot closer to answering the question for yourself.

But Still, What About Bias?

It’s a fair question. But the question is also its own answer, in a way.

Yep, we cover LED grow lights extensively.  But if we didn’t think LED grow lights were worth buying, why would we bother to do that?

We’ve been in the same situation you are now—trying to decide whether LED grow lights really are the best option for growing weed indoors. And it’s true, some LED grow lights still aren’t great.

But we weighed up the evidence and concluded that LED grow lights are here to stay. And, moreover, that the overall standard is only getting better.

We still think that.  Here’s why.

Why We Think LED Grow Lights Are The Best Light Source For Growing Weed Indoors

For indoor weed-growers, the standard grow light choice comes down to HID, fluorescent, CMH, and LED.

We’re going to rule out fluorescents immediately.

They’re OK for very tiny grow spaces because you can get them very close to your plants. However, their light doesn’t penetrate as far as LEDs or HIDs, so in later stages, you need to swap to a different grow light for best results. Or learn to train plants to grow short and flat.

And the clinching factor:  They give the lowest yield per watt. Two to four times lower than HIDs or LED grow lights.

What about CMH Lights?

We have written an article about CMH lights and MaryJane Farmer has two observations.  First, CMH is HOT and usually requires significant cooling equipment, like air conditioning.  Second, CMH means you also have to buy and regularly replace the ballast and the lamps, which are both expensive and a pain in the butt.  Not suitable for small indoor growers, in MaryJane’s opinion.

So What About HID Grow Lights?

Can HID lights produce good weed in high quantities?  Absolutely.

Growers have been using them successfully for decades. There’s no disputing whatsoever that they’re a great source of light for cannabis plants. We’re not even going to try.  But are they the best for growing weed indoors?  Are they the best for indoor growers who are not running an industrial capacity operation?  MaryJane thinks not.

And for that matter what do we mean by “the best”?

So let’s try to clear things up a bit…

What Do We Mean By “The Best”?

For us, it comes down to this question: What do we want from a grow light when growing cannabis? We think the most important requirements are:

  • Better yields.
  • Higher quality, more flavorful buds.
  • Better energy efficiency—more product for the electricity used, less energy wasted.
  • Brightness and intensity—light that can penetrate below the canopy to nurture the whole plant.
  • Even coverage—fewer “hotspots”, less need to rotate your plants.
  • Correct spectrum—produces only light that the plants can actually use.

Those are our judging criteria.

Other factors, like convenience, come into it too. But the question here is primarily about the best light source for growing weed. That is, about which kind of grow light cannabis best responds to.

And to make it a fair fight, we’re comparing the best to the best.

The Best LED Grow Lights Outperform The Best HIDs

Why does MaryJane Farmer say that?  Let’s start with the spectrum.

Light Spectrum

No other lights are as adjustable and customizable in terms of light wavelengths. LED grow lights can be fine-tuned to produce only the wavelengths most beneficial to your cannabis plants.

You can keep it simple with a full spectrum light for the whole grow. Or at the other extreme, you’ll find cutting-edge panels where the spectrum can be programmed and automated in the minutest detail—the ratio of red to far reds will even change throughout the day to mimic the sun’s progress through the sky.

Metal Halide (MH) grow lights are great for the veg stage and can be used for the whole grow. High-Pressure Sodium (HPS) lights have a great spectrum for flowering. But both still give off plenty of light that your cannabis just isn’t using.

This brings us to energy efficiency.

Energy Efficiency

There’s no disputing that LED grow lights are more efficient.

Much less wattage is consumed to produce the same brightness as equivalent HID bulbs. Partly that’s because more of the light emitted is absorbed by your plants if your light is producing the right spectra (wavelengths), but also because LEDs convert electricity into light extremely efficiently—very little electricity converts into heat instead.

Less heat means even more energy savings because you’ll need very little extra cooling in your grow area. Especially when compared to much hotter HID bulbs.

Remember that HID, HPS, CMH, and even fluorescent lights produce their light by burning the gas inside the glass tubes.  In other words, the light is coming from a FIRE.  That means HEAT but it also means replacing the gas-filled tube when the gas is used up.  So for these reasons, LED Grow Lights are more efficient and less hassle.

Brightness and Intensity

This used to be where HID grow lights had the edge. But now, the best quality LED grow lights can literally outshine them.

Many of the older, high-ranking, LED-skeptic articles you see in Google’s results are from back when 1W LED chips were common and 3W chips were pretty much cutting edge.

These days chips in LED grow lights are much brighter and often accompanied by sophisticated optics to focus and intensify the light their diodes produce. Now, highly efficient 5W such as those led’s found in this grow light review. 5W and above chips and (COB) arrays are common and will easily penetrate the canopy to the lower leaves.

Evenly though?

Even Coverage

Well, even though the light from LEDs is naturally very directional, the aforementioned sophisticated optics mean “hotspots” are less and less of an issue.

With older LED grow lights, your plants got very intense, concentrated light below each individual diode, but much less light between and around diodes.

And that’s still a problem with some cheaper lights from no-name companies.

But if you do your homework and buy from manufacturers who’ve been around awhile, built up a reputation, and can give you detailed coverage maps (if they can’t, steer clear), then you should be fine.

Light from HIDs is naturally diffuse and fairly evenly spread. So the majority of HIDs probably give more even coverage than the majority of LEDs.

However, a certain amount of light energy from HIDs is wasted by being reflected off multiple surfaces before it reaches your plants. So there’s a trade-off.

And the best LED lights give pretty even coverage.

Bud Quality, Flavor, Potency

marijuana bud

Another benefit of LED grow lights is that they can help you bring out the flavors and potency of the weed you’re growing.

A fuller spectrum, including certain wavelengths of ultraviolet light, stimulates resin production. Which means higher levels of THC, terpenes, and certain cannabinoids.

Better Yields

This is still a bit of a controversial one…

Mainly because it can take a bit of experience and experimentation to get the maximum effectiveness from your LED grow lights.  But growers using LEDs are increasingly finding that they can equal and outperform equivalent HID grow lights for yields.

Even if yields were merely equal, though, or even slightly less with LEDs, we feel that the much lower running costs of LED grow lights would still make them the better, more economical choice.

MaryJane’s Advice

If you want to know what the best light source is for growing weed indoors, we think the best LED grow lights have the edge. Moreover, there are more and more LED grow lights out there that are worth buying.  Here is my article on cost-effective LED Grow Lights.

However, when it comes to a fast-moving technology like LEDs, there’s no substitute for doing your own research.  Because LED grow light technology has moved forward at such a pace in recent years that even Google’s search results can’t keep up!

Right now, type in a query about LED grow lights, and often Google’s first few pages will paint a very outdated and inaccurate picture of what LED grow lights can do.

But check the age of the articles you find, and the age of the articles they cite and link to, make sure it’s actually today’s LED technology that’s being discussed, and you’ll soon see exactly why we’re so optimistic.

And don’t forget to check our LED Grow Lights Page for some of the most recently released up-to-date lights.

I value your advice, your questions, and your comments–even your criticisms.  Fire away with comments below.

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