Grow Lights for Weed

Reviews of the 5 Best Grow Lights for Marijuana

As more and more states legalize cannabis for cultivation and personal use, the interest in growing your own weed at home has never been so high. It comes as no surprise that many people are choosing to grow their own marijuana using indoor hydroponics techniques instead of traditional soil-based methods. This is because hydroponics offers many benefits like faster growth, higher yields, fewer pests, and a more discreet way to grow cannabis to its fullest genetic potential. But producing high-quality marijuana doesn’t come easy. It starts with a good hydroponics system for marijuana and a setup that includes the best grow lights for weed.

One of the most important decisions an indoor hydroponics grower will make is how their plants will receive adequate light to power them through the vegetative and flowering stages of growth. In fact, grow lights for weed are possibly the single most important element in achieving healthy plants, high yields, and big buds. Let’s look at some of the principal things you should consider before purchasing a grow light for weed, and then review 5 of the best marijuana grow lights on the market today.

Grow Lights for Weed: The Requirements

In the absence of natural sunlight, grow lights play a critical role in indoor gardening.  Light is necessary to bring about photosynthesis, during which water, carbon dioxide, and light provide the energy source for plants to produce glucose and oxygen for their growth. As you search for a suitable grow light for weed, you should first consider the following:

Color 

Different light sources provide different colors, each with varying energy outputs and wavelengths. Plants need more blue light during the vegetation phase and more red light during the flowering stage. Blue waves tend to be smaller and possess more energy whereas red light waves have a longer reach but with less energy output. Full-spectrum grow lights contain all colors of the sun and therefore appear white.

Light Intensity

The brightness of the light determines how much light energy can be absorbed by the plant. Intensity is measured in Lumen output.  Low intensity grow lights often produce long, leggy plants because they reach to find an adequate amount of light. High-intensity lights are superior for growing cannabis because they produce more dense, compact, and higher yielding plants.

While you can somewhat increase the intensity by moving the grow lights closer to the plants, it’s best to choose a high intensity grow light from the start.  For great results, you want something that is capable of delivering the high-intensity light with a broad spectrum of colors.

Grow Light Cycle for Weed

 When growing cannabis, the vegetative stage of plant growth requires a longer duration of light than does the flowering stage. Some grow lights have built-in timers for light cycles (automatically turning on/off lights at set times), while more basic grow lights (without this capability) will need a timer.

See our Marijuana Growing Supplies page for timers and other cannabis growing supplies.

Generally speaking, you should follow the following lighting cycle for weed:

Vegetation Stage: 18 hours of light / 6 hours of darkness

Flowering Stage: 12 hours of light / 12 hours of darkness

Different Types of Grow Lights for Weed

Fluorescents

There are two types of Fluorescents: CFL and T5 grow lights. CFL lights are usually twisted in their shape, while T5 grow lights are long and narrow.

Fluorescent grow lights have warm, cool, or full spectrum colors. They are inexpensive, can be used in a standard lighting socket, give-off a pleasant color for indoor environments, provide good temperature control, and have low electricity consumption. The downside is their penetration is less intense. As such, fluorescent lighting tends to produce smaller yields per watt vs. HID and LED, as well as smaller and fluffier buds.  They need to be positioned very close to the plant to be effective. Thus, they are not recommended for taller, full-sized cannabis plants. Be aware that fluorescents also contain a small amount of mercury.

Bottom Line

Fluorescents are inexpensive, can be effective, and don’t consume a lot of electricity. However, if you want dense, high trichome buds, fluorescents are not your best choice.  They do make for a decent supplemental light source to your other grow lights.

High Intensity Discharge (HID)

High-Intensity Discharge (HID) grow lights are a step above fluorescents in efficiency and are a favorite among expert growers. They have an awkward shape and are normally used in conjunction with a reflector hood to direct light down towards the plants. The disadvantage to HID lighting their tenancy to running very hot, so exhaust fans are often used to vent a grow tent or greenhouse.

Besides ventilation and temperature control, they may also require specific lighting fixtures and ballasts (to mediate the electric currents).

So while the initial investment in the light may be lower than LEDs, they do require more investment in other ways, as well as changing light bulbs more often.

The three types of High-Intensity Discharge lighting are Metal Halide (MH), High-Pressure Sodium (HPS), and Ceramic Metal Halide (CMH, LEC, Light Emitting Ceramic). Metal Halide’s blue hues are particularly good for vegetative growth, while HPS yellow lighting is great for the flowering stage and produce an amazing yield per watt. Ceramic Metal Halide lighting is manufactured with ceramic, thus making them more efficient than standard MH lights.

Bottom Line

HID / MH lights can produce high yields and super quality buds. However, the grow light setup requires more maintenance and safeguards to prevent heating issues.

LED Grow Lights

While HID lighting is certainly efficient, the heating issues are a concern. If you read our Best LED Grow Lights article, you know the primary benefit of LED grow lights is that they can significantly reduce heat output and power consumption vs other lighting sources.  LED grow lights often have built-in fans and heat sinks to regulate temperature and ventilation, and they are more energy efficient overall. While the initial cost is higher than the alternatives, LED grow lights can actually save you more money in the long run.

LED grow lights are plug-n-play. You can simply hang a grow light over your plants and plug it directly into the wall without any other major adjustments.

Better LED grow lights can produce the particular spectrum a plant needs for its various stages of growth.

Another advantage is their longevity; LED bulbs will not need to be replaced nearly as often as fluorescents or HID.

Because of their numerous benefits, we recommend LED grow lights to hydroponics marijuana growers – beginners and experts alike.

Bottom Line

LED grow lights are cost-efficient, low maintenance, and have a lifespan of many years. Some cannabis growers use LED grow lights in conjunction with High-Intensity Discharge lights to produce high-quality buds, but they can be used as a stand-alone grow light for weed with amazing results.

Best Grow Lights for Weed

Now that we recognize which elements of grow lights are important – and which types of grow lights work best – let’s take a look at 5 of the best grow lights for marijuana.

More Grow Lights for Weed

Here are a few more top-rated and best-selling grow lights for weed. They didn’t quite make our top 5 list, but they are still worthy of your consideration!

Thanks for reading our Best Grow Lights for Weed article. We hope that you found a light for your next cannabis grow. For more hydroponics and aquaponics articles, please see our LED Grow Light Reviews,  Grow Cabinets for Weed, Grow Tent Kits, Hydroponics Growing Medium, and Hydroponics System pages.