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The Different Types of Lights for Cannabis: Pros and Cons

Learning about the many types of grow lights available can be overwhelming, especially for those new to cannabis cultivation. They all serve the same purpose, but many of them go about it in different ways. To clear up the confusion, we’ll be taking a look at the different types of lighting, and breaking down their pros and cons.

Let’s run through a detailed comparison of the most popular cannabis grow lights.

Contents:

Every cannabis cultivator knows how important proper lighting is when it comes to achieving a successful harvest. Along with nutrition and water, it’s one of the most crucial factors in ensuring healthy growth and bountiful yields.

Although natural sunlight is usually optimal for cannabis growing, many cultivators prefer to grow indoors for various reasons. First, not everyone lives in a climate where outdoor growing is feasible. Second, indoor growing involves timed artificial lighting, giving the grower more control over the vegetative and flowering phases of their cannabis.

With that in mind, we believe exploring the world of cannabis grow lights is more than worth it.

Pros and Cons of Different Cannabis Grow Lights

Today, you can find many different types of grow lights for indoor cultivation. But not all are equal; in fact, there are big differences when it comes to effectiveness and cost. In turn, some grow lights may be better suited for certain types of setups than others.

Let’s take a look at the types of grow lights available, and compare them relative to their pros and cons.

FLUORESCENT (CFL) GROW LIGHTS

CFLs, also known as “compact fluorescent lights”, are some of the most common you’ll see out there. You can get these lights at many places, including home improvement stores and even grocery stores.

FLUORESCENT (CFL) GROW LIGHTS

CFLs, also known as “compact fluorescent lights”, are some of the most common you’ll see out there. You can get these lights at many places, including home improvement stores and even grocery stores.

They are especially suited to small grows, and will be the most affordable starter lights you’ll find. Conveniently, these bulbs have standard sockets so you can use them with any standard light fixture. They do not require any special equipment.

You can find “daylight” CFL bulbs at 6500K or “warm white”, with a more reddish light spectrum, at 2700K. Bulbs with a daylight spectrum are more suitable for the vegetative growth phase, while warmer CFLs are better for the flowering phase.

CFL PROS CFL CONS
Low cost and widely available Low light output (only suitable for growing 1–2 plants)
Easy to set up and use Not optimal for flowering (produces subpar yields)
Good for beginners Tends to have a shorter lifespan than other lights
Available in various wattages and colour temperatures
Uses little electricity, saves energy
Doesn’t get hot
Perfect for clones and seedlings
CFL PROS CFL CONS
Low cost and widely available Low light output (only suitable for growing 1–2 plants)
Easy to set up and use Not optimal for flowering (produces subpar yields)
Good for beginners Tends to have a shorter lifespan than other lights
Available in various wattages and colour temperatures
Uses little electricity, saves energy
Doesn’t get hot
Perfect for clones and seedlings

CFL Cost and Expected Lifespan

A standard 40W CFL bulb will only cost a few bucks. This makes them great starter lights for growers on a budget! It’s a lot of bang for your buck, too, as the expected lifespan for compact fluorescents is about one year.

Yield per CFL

Expect to obtain 0.3 grams per watt (roughly 12 grams per standard light).

HID (MH and HPS) Grow Lights

HID (high-intensity discharge) grow lights are somewhat of a gold standard in the cannabis cultivation industry. Many growers swear by HID lighting and believe that they produce the best and biggest yields.

HID (MH and HPS) Grow Lights

HID (high-intensity discharge) grow lights are somewhat of a gold standard in the cannabis cultivation industry. Many growers swear by HID lighting and believe that they produce the best and biggest yields.

There are two main types of HID lights: MH (metal halide), and HPS (high pressure sodium) lights. The difference between the two is that MH lights produce a “cooler”, blueish light, whereas HPS lights are usually red. This makes MH lights more suitable for the vegetative phase, with HPS lights being better for flowering.

Therefore, most advanced growers use a combination of MH and HPS bulbs for the duration of the process. If, for some reason, you need to choose one type of HID for the entire grow, we would recommend HPS lights. 600W HPS lights are the most popular type. In most cases, you can usually get complete sets that include the bulbs, a ballast, and a reflector.

HID PROS HID CONS
Compared to high-end LEDs, HID grow lights cost less outright They give off intense heat that can spike grow room temps or burn plants
Easy to set up and operate, even for relative beginners You’ll need additional equipment to operate them, including an electronic ballast and reflector
Produces excellent yields HID bulbs degrade over time, and you will have to replace them periodically
Reliable and consistent HID lights are very power-hungry and can significantly increase electricity bills
Options for growth and flowering
HID PROS HID CONS
Compared to high-end LEDs, HID grow lights cost less outright They give off intense heat that can spike grow room temps or burn plants
Easy to set up and operate, even for relative beginners You’ll need additional equipment to operate them, including an electronic ballast and reflector
Produces excellent yields HID bulbs degrade over time, and you will have to replace them periodically
Reliable and consistent HID lights are very power-hungry and can significantly increase electricity bills
Options for growth and flowering

HID Light Costs and Expected Lifespan

As discussed, you can find complete HID lighting kits that include a lamp, a ballast, and a reflector for €150 and up. The low initial cost, however, will be offset by the higher operation cost (i.e. your electric bill).

The bulb lifespan is approximately one year. In turn, you should replace your bulbs annually to maintain optimal light output.

Yield per HID Light

You can expect around 0.5–1g+ per watt, which is roughly 300–600 grams/standard light.

LED GROW LIGHTS

Just a few years ago, LEDs were not suitable for “serious” grows, aside from providing light for seedlings or clones. However, LED technology has come a long way in a short time.

LED GROW LIGHTS

Just a few years ago, LEDs were not suitable for “serious” grows, aside from providing light for seedlings or clones. However, LED technology has come a long way in a short time.

Most quality LEDs emit a light that works for both veg and flowering, while some come with a switch to change the light spectrum according to the appropriate phase. Modern LED grow lights, such as those with COB (“chip on board”) technology or “Quantum boards”, can now provide solid light intensity and penetration, even for the most demanding grows. Today, LEDs can rival, or even surpass, other types of grow lighting, including HID lights. That being said, you need to get the right ones. These lights tend to be some of the most expensive, but they can also save you some serious money in the long-run.

LED PROS LED CONS
Most energy-efficient type of grow light (saves money and energy over time) High-quality fixtures with modern modules can put a decent dent in your wallet
LED lights run much cooler compared to HID lighting, barely producing any heat at all There is no industry standard for LED lights
Cuts back on cooling costs and reduces risk of burning plants Cheap models on the market produce inferior results
Most commercially available LED grow lights are “plug and grow”—no special ballast required Potentially lower yields than HID
Streamlined; can support both veg and flower
LED PROS LED CONS
Most energy-efficient type of grow light (saves money and energy over time) High-quality fixtures with modern modules can put a decent dent in your wallet
LED lights run much cooler compared to HID lighting, barely producing any heat at all There is no industry standard for LED lights
Cuts back on cooling costs and reduces risk of burning plants Cheap models on the market produce inferior results
Most commercially available LED grow lights are “plug and grow”—no special ballast required Potentially lower yields than HID
Streamlined; can support both veg and flower

LED Light Cost and Expected Lifespan

You may find a low-quality LED fixture for a single plant for €120. But for good LEDs from a reputable brand, expect to pay several hundred euro, even up to €2,000. You get what you pay for with LEDs, so it’s always worth doing your research and finding a reputable brand.

Good LED grow light fixtures have a lifespan of 5–10 years.

Yield per LED Light

0.5g–1.8g per watt, depending on the make/quality of the light.

LEC GROW LIGHTS

LEC lights, also called ceramic metal halide (CMH) or ceramic discharge metal halide (CDM) lights, are the last type we’ll be discussing today.

LEC GROW LIGHTS

LEC lights, also called ceramic metal halide (CMH) or ceramic discharge metal halide (CDM) lights, are the last type we’ll be discussing today.

The name also hints at the difference between LEC lights and conventional HID lights. LEC lights use a ceramic arc tube, rather than the quartz version found in regular MH lights. The result is a more natural colour, more lumens per watt, and a longer lifespan. LECs include built-in ballasts, so that aspect of setup is very simple.

While modern LED lighting is now becoming the de-facto standard in most grow rooms, LEC lights do have certain benefits. This makes them an interesting alternative to other types.

LEC PROS LEC CONS
Emits a natural light spectrum (easier to see your cannabis and spot issues) UV-B light is harmful to humans (safety equipment is needed to reduce risk to skin and eyes)
LEC lights give off UV-B rays that may improve yield or trichome production High setup cost
Simple setup and operation Generates lots of heat
Longer life-span than HID lights Slightly less powerful than HID lights
UV-B rays are blocked by glass
LEC PROS LEC CONS
Emits a natural light spectrum (easier to see your cannabis and spot issues) UV-B light is harmful to humans (safety equipment is needed to reduce risk to skin and eyes)
LEC lights give off UV-B rays that may improve yield or trichome production High setup cost
Simple setup and operation Generates lots of heat
Longer life-span than HID lights Slightly less powerful than HID lights
UV-B rays are blocked by glass

LEC Light Cost and Expected Lifespan

Decent LEC grow light fixtures start at €250–300, with higher-end models setting you back up to €1,000. The bulbs also cost somewhat more than normal MH/HPS bulbs.

On the plus side, LEC bulbs will last about twice as long as HID ones, approximately two years.

Yield per LEC Light

When utilising LEC lights, you can expect up to 1.5g per watt.

Which Lights Are Best for Growing Cannabis?

So, what type of grow lighting is best? This is a decision that will depend on various factors, including the size of your growing area, the type of weed you’re growing, and, last but not least, how much you can spend.

If you require a light for seedlings and clones, or you happen to have a “micro grow” in a very small space (like a cupboard), you are likely best off with a simple CFL light.

For slightly bigger grows, consider a decent LED light anywhere from 400–600W. As there won’t be much heat from the light, you may be okay with a simple exhaust system and a fan.

For medium to large growing operations, you can look into high-end LED fixtures and LEC lights, or go with proven HID lighting solutions.

Don’t Just Look at Wattage — Power Equivalents Between Types of Lights

Now, be aware that a 200W CFL isn’t the same as a 200W light LED, and neither are the same as a 200W HID. The wattage only indicates how much power the fixture uses, not saying anything about the light output. Because lighting technologies differ in their efficiency, you can’t compare them based on their wattage alone. The only type of light where one can expect certain yields (given a particular wattage) would be HID lights, as these are standardised.

Likewise, this also means that a LED fixture stated as being 600W doesn’t necessarily emit the same amount of light (and therefore produce the same yields) as, say, a 600W HID light. Honestly, the only way to determine true light output is to go over the specs from the manufacturer. Better yet, ask other growers for their experiences with a particular make or type of light—that way you’ll know what to expect.

Lights, Lights, Lights: Illuminating Your Options

Choosing the right grow light for your cannabis is among the most important decisions you’ll make.

If you want superb yields, you definitely can’t bypass getting at least a 600W or stronger HID light, or an equivalent LED or LEC. If, on the other hand, you’re looking after seedlings and clones, a less powerful CFL will do.

Most importantly, don’t spend money on a grow light without getting informed at first. A great “bargain” may ultimately just be a waste of your hard-earned cash. If prices for a good light are intimidating, you can also look into DIY solutions! You can find all sorts of kits online that come with the necessary parts. That way, you can save some money while getting a quality light that will serve you and your plants well.

In this article, we’ll be comparing grow lights made for indoor cannabis cultivation, looking at their pros and cons, and seeing what lighting solution is best.

How Many CFLs Per Plant (Using Watts And Size)?

Last updated June 11, 2020 By Steven 22 Comments

I get this question a lot.

Everybody wants to know how many CFL bulbs are needed per plant.

But how can you answer that without a little more info?

I mean, how large is the plant?

What is the wattage on the bulbs?

In order to accurately tell you how many CFLs for one plant, I need to know those two variables at least.

That said, I can still help, even without them.

You’ll need to do a little (very simple) math on your own, but together, we can figure out exactly how many CFL bulbs you need to light your garden.

Let’s begin by figuring out what you’ll need to light one plant, since everyone always asks about the lighting needs per plant.

How Many CFLs For One Plant

As mentioned above, plants vary greatly in size.

For that reason, we need to use a standard measurement to determine lighting needs. The easiest to use is the square foot.

When using CFL bulbs to grow a plant with a high light requirement (like cannabis), you want a minimum of 60 watts per square foot.

Ideally, you want 100 watts per square foot.

And it doesn’t hurt to go higher (though there’s not much point going over 150w). You really can’t give your plants too much CFL light.

Those numbers are for the flowering stage. For the vegging stage (or for seedlings or clones), you could cut that in half. I’d shoot for around 60 watts though. The same goes for plants with a lower light requirement.

Actual Watts Or Equivalent Watts?

Compact fluorescent lamps usually have two wattages listed on the packaging: one is the actual wattage that the bulb consumes and the other is the incandescent equivalent.

For example, a CFL that is equivalent to a 100 watt incandescent bulb will actually use around 23 to 28 watts of power.

When I say you want to aim for 100 watts per square foot, I am referring to the actual wattage.

So, to continue with the bulb from the example: you would want 4 of these bulbs, not one of them. The actual wattage counts.

If you have two larger plants that each take up 3 square feet of space, you would want 300 watts per plant, or 600 watts total. That would mean 24 of those 23-28 watt bulbs from the example.

Note: once you have more than a plant or two, it makes more sense to get a T5 fixture or a cheap LED light. CFLs are great for a small grow, but once you get up to 10 (or even 5, in my opinion) bulbs, it just becomes too much work to keep readjusting the lights, due to the rapid plant growth.

Where Do I Put The Compact Fluorescent Bulbs?

Ideally you want to surround your plant(s) with CFL bulbs, so that they get light from every side. Most people asking these questions are looking to grow marijuana, so let’s focus on that plant for a bit.

First make sure you plant grows the right way

You can choose how your plant grows. Weed plants grow upward into a Christmas tree shape naturally, but that is not good for us. This results in one large bud at the top and several smaller buds below.

You want to force your plant to grow short and fat. That way they are more flat on top and can grow multiple large buds. You can get them to grow this way by bending and tying down various stems to get them to grow outward.

If you force the main stem to grow horizontally from the beginning, other stems will grow upward from it, creating a shorter and fatter plant naturally. You’ll find much more on training your plants to grow the way you want here.

Then put your bulbs in the right spots

If you have a short and fat plant, there is no need to hang bulbs below the canopy. Hang them all above, with some off to the side and a bit lower, so that they are next to the top of the plant.

Anywhere you see a shadow area, put a bulb there. If you do not have enough bulbs to fill all the shadows, that means you need more bulbs.

CFL bulbs can generally hang fairly close to your plants, but this does depend on their wattage. A 20 to 30 watt bulb can hang within a few inches.

You can always use the “back of the hand test” to see if your bulb is too close. Hold you hand where the plant is, with the back of your hand facing the bulb. Keep it there for 30 seconds. If your hand gets too hot, then it will also be too hot for the plant. Back the bulb off a bit.

Weed plants grow rapidly, so keep a close watch to make sure they don’t grow into the bulbs and get burned. They can grow several inches in a day, so if you won’t be around to keep an eye on them, make sure to position the bulbs a bit further away.

If you have a plant that is growing tall, you may want to get some light on it from beneath as well, or at least from the sides. This will depend on the plant, however. If you are growing cannabis, you will get a much better yield by not growing tall plants, so I highly recommend keeping them short and fat.

Do I Need Special Grow Bulbs?

In fact, I would encourage you not to buy special CFL grow bulbs. They are generally much more powerful, so you would only have one or two above the plant, ideally in a reflector.

The problem is that fluorescent bulbs do not have great penetration. That is why you hang them so close to the pants. With fewer powerful bulbs, you have to hang them further away and are more likely to get shadows. More bulbs that are less powerful allow you to hang them close and to completely bathe your plant in light.

In addition, bulbs that are specifically labeled as grow lights are almost always overpriced. Regular old fluorescent bulbs are every bit as good and do exactly the same thing, but they cost far less.

The main thing to look out for is the color temperature. There are cool white bulbs that have a color temperature around 6000K to 7000K (‘K’ stands for Kelvin), warm white bulbs with a color temperature around 2000K to 3000K, and neutral bulbs with a color temperature in the middle, around 3500K to 5500K.

The cool bulbs (with a higher color temperature) are better for vegging, since they contain more blue light in their spectrum and the warmer bulbs are better for flowering, since they contain more red.

You best bet would be to have a ratio of 2 cool to 1 warm for vegging, then add a few more warm ones for flowering. That way you also add more wattage for flowering and plants need more wattage then than they do during vegging anyway.

Where do I get CFL bulbs?

You can buy CFL bulbs pretty much anywhere. If you want to get them online, Amazon has some good options. Their value packs are especially good deals. You can get all the bulbs you need in one pack.

If you don’t have light fixtures for these bulbs (they fit in any standard lamp fixture), you can simply buy cords with a socket on the end like these.

Everybody wants to know how many CFL bulbs you need per plant, but that obviously depends on the size of the plant and the bulbs. An easy way to figure out what you need is to…