Cannabis needs light to grow, and unless you live somewhere with a perfectly sunny, Mediterranean climate, you’re probably better off growing cannabis indoors with artificial lights. The good news is – indoor lighting allows you to control exactly how many hours of light your plants receive each day – no matter what the weather is like outdoors. But should you go with an LED or an HID? And how exactly do you use grow lights for cannabis cultivation?
Here’s a closer look at our recommendations for the top grow lights in 2021:
- Price: $850
- Life span: 50,000+ hours
- Coverage area: 16 square feet (flowering stage), 36 square feet (vegetative stage)
- Wattage / strength: 600 watt
- Size: 18’’ x 8.5’’ x 4’’
- LED or HID: LED
- 3 highlights: Same strength as 600 watt high pressure sodium light and uses 40% less energy (according to the company), fully programmable spectrum control, can cover up to 36 square feet in vegetative phase.
The SolarSystem 550 is a highly-efficient LED system that works great for small-scale home grows and can be scaled up for larger commercial operations.
The light system also has fully programmable spectrum control, though this requires purchasing the SolarSystem controller separately. The company also states that the light is especially easy to install and never needs bulbs.
Also, it comes with a 5 year warranty and has an LED lifetime rating of 50,000+.
- Price: $369
- Life span: 50,000 to 100,000 hours
- Coverage area: 4.5’x3.8′ in vegetative state (3’x2′ at 18″ height)
- Wattage / strength: 180 watts in flowering stage, 93 in vegetative stage
- Size: 9’’ (width) x 19’’ (length) x 3’’ (height)
- LED or HID: LED
- 3 highlights: 5 year complete warranty and free shipping, very long lifespan, dual light spectrums for vegetative and flowering stages.
The Platinum LED P300 is an affordable, efficient, and powerful indoor cannabis LED grow light that produces the same light of a 400 watt high power sodium light, while only consuming 180 watts of power, according to the company.
Platinum states the light provides a blend of 12 different bands of light spectrum and integrated 90 degree secondary focusing lenses to help the light penetrate deep into the canopy. The lights also have separate spectrums for the vegetagive and flowering stages.
In addition, the lights have a lifespan of 50,000 to 100,000 hours and come with a 5 year complete warranty, one of the longest available anywhere.
- Price: $1,099
- Life span: > 50,000 hours
- Coverage area: Up to 4.25’ x 4.25 in flower stage, 5.25.’ x 5.25’ in vegetative stage
- Wattage / strength: 840 watt (true wattage 420 watts)
- Size: 15.75″ x 15.75″ x 5″
- LED or HID: LED
- 3 highlights: Appears white to allow easy gauging of plant health, heavy duty light hangers included, directs more light directly to flowers and leaves
The team at Black Dog LED is known for producing top of the line LED lights for professionals and amateur growers, and the PhytoMAX-2 400 is the ideal size for an indoor grow of up to about 6 plants.
The light system is highly efficient, and Black Dog states that it outperforms 600 watt high power sodium lights while using far less energy. It also directs more light to the flowers and leaves, instead of the stems of the plant, according to the company.
The lights also appear white to the human eye, making it easier to assess plant health. The light system is one of the smaller made by the company, but can still cover more than 16 square feet of space in the flowering stage, and 27 square feet in the vegetative phase. The company also produces the smaller PhytoMAX-2 200 for growers looking for the ideal solution for growing one single plant.
- Price: $119
- Life span: 32,000 hours for HPS light, 12,000 hours for MH light
- Coverage area: 4’ x 4’
- Wattage / strength: 400 watts
- Size: 21’’ x 5’’ x 17’’
- LED or HID: HID
- 3 highlights: A great all-in-one value, comes with heavy duty hangers and mechanical timer, automatically converts between HPS and MH bulbs
At only $119.95, the iPower 400 watt digital grow system can produce an instagram-ready indoor cannabis grow at a fraction of the cost of many LED systems.
The kit comes with a wing reflector hood sect, heavy duty hangers and a 24-hour mechanical timer, as well as a digital dimmable electronic ballast to provide full control and maximize the lumens provided to the plants.
iPower notes that the system does produce a lot of heat so good ventilation is a necessity.
Nonetheless, with the iPower kit, growers have an affordable way to light a 4’ by 4’ indoor grow with a well-balanced spectrum of light.
- Price: $89
- Life span: Company does not say, but comes with a 2 year warranty
- Coverage area: 3’ by 3’ in vegetative stage 2’ by 2’ in flower stage
- Wattage / strength: 150 watts
- Size: 18.1’’ (length) x 11.8’’ (width) x 6.9 ‘’ (height)
- LED or HID: HID
- 3 highlights: lightweight and easy to set up, low heat output, affordable
The Sun System 150 watt is a smart option for home growers who don’t have a huge budget and are only looking to grow a single plant from seed to harvest.
It can cover an area of 3’ x 3’ in vegetative stage and 2’ by 2’ in flowering, and provides 16,000 lumens according to the company. It also comes with vented housing to reduce the heat and intensity of the light. And for a light that costs less than $100 it still has a one year warranty on the lamp and two years on the fixture.
Also, the lighting system comes with everything you need to get it mounted and set up in no time.
- Price: $229
- Life span: 24,000 hours for HPS bulb, 10,000 hours for MH bulb
- Coverage area: Around 6’ by 6’
- Wattage / strength: 600 watts
- Size: 19’’ (length) x 17’’ (width) x 8’’ (height)
- LED or HID: HID
- 3 highlights: 12 week grow guide included, easy to operate, covers a large area at a low price
The 600W HID lighting kit from Yield Lab is a great option for growers who would like to cultivate a slightly larger indoor area, but don’t have a huge budget or any real expertise in light installation.
The system comes with a 600 watt HPS bulb and 600 watt MH bulb, as well as a digital dimmable ballast to provide complete control and peace of mind. In addition, a hood reflector is included to boost the light output to the plants. Both lights are covered by a one year warranty and the dimmer is covered for 3 years.
Also, the kit comes with heavy duty hangers and a mechanical timing switch to help with setup and operation.
How to use a marijuana grow light
First things first, you’ll need to determine how much light you need. Usually, with HPS bulbs around 250 watts should be enough for 2 plants, while 400 watts should have you set for 4 plants. A 600 watt set up should provide enough light coverage for 8 plants, which should be more than enough considering that most legal marijuana states only allow personal cultivation of up to around six plants. LED lights typically cover more area with less wattage, and you should be able to cover 6-8 plants with only 350 watts and four plants with only 280 watts according to company provided information.
Lights produce a lot of heat, so you’ll want to make sure they aren’t too close to the tops of the plants, in order to keep from causing any damage. If you hold your hand under the lights at the level of the top of the plants and it feels too hot for you, you’ll want to raise them a bit. This also depends on the power of the light. For smaller, 150 watt lights, about a foot above the plant canopy should be enough, while with a 600 watt light you’ll want to hold it between one and two feet above the canopy.
This can vary widely from one brand to the next though, so your best bet may be to follow the manufacturer’s recommendations on whichever light you purchase. Alternatively you can download a Lux Meter on your phone to provide a more accurate reading to understand the output of your light, allowing you to adjust the height for optimal growth.
In your grow space, you’ll also want to make sure that you have a proper ventilation system setup. Lights produce a lot of heat, and proper ventilation – including the use of fans – will help control temperature somewhat, and help prevent mold.
Also, your lighting system may require a large number of outlets to cover the lights, ballast, fans, and any other equipment you have. For safety’s sake, make sure not to overload any single outlet and ensure you have a surge protection plug to protect your equipment from electricity cuts and surges which can cause damage to your hard earned equipment.
The lighting schedule and vegetative vs flowering stage
Cannabis plants have two distinct growing phases – vegetative and flowering. When growing cannabis outdoors, the plants usually begin flowering (producing buds) when the days become shorter as summer shifts to autumn. Indoors, there are no seasons, so growers can “trigger” the flowering stage by artificially mimicking the seasonal shift by adjusting the hours of light the plants receive per day.
During the vegetative stage, growers tend to give the plant an 18/6 lighting schedule, or 18 hours of light and 6 hours of darkness (other combinations include 17/7 or 19/5, anything that isn’t 12 hours of darkness).
By shifting to a 12/12 schedule, growers can trigger flowering. Flowering too early can mean a smaller yield while waiting too long to flower your plants can result in plants too big for your grow tent or indoor room. Harvesting your flowers too soon or while clear trichomes are present will result in a smaller harvest with less terps and potency, while harvesting too late can result in too many amber trichomes which can cause the flower to be harsh and sedative for the user. With some strains, the vegetative stage can range from around 2-4 weeks to somewhat longer, which is all dependent on the sexual maturity of the plant. With clones, this stage is significantly shorter.
If in doubt, speak to the seed provider about the vergetative and flowering stages of the particular cannabis chemovar and when triggering is recommended.
LED vs HID lights
Most indoor grow lights in use today are divided into two main categories – light-emitting diode (LED) lights and high-intensity discharge (HID) lights.
HID lights include metal halide (MH) and high-pressure sodium (HPS) lights, and HID grow systems often use a combination of the two in order to increase yields. These lights tend to produce more heat and require more energy than LED lights. This means you may need more height in your grow space to keep the lights further from the plants.
LED lights are typically more energy efficient and give off less heat. This can mean that they are more safe, but looks can also be deceiving. Because the lights don’t appear to be working as hard, it can be easy to underestimate the light your plants are receiving, potentially resulting in light burn. Also, they tend to have a higher price tag than HID lights.
Which weed lamps are better?
There is no black and white answer to this question. LED lights allow more customization in the light spectrum meaning that they can be easily adjusted for the vegetative and flowering stages. They also produce less heat, are more energy efficient, and last longer. At the same time, they can cost significantly more – even to an extent that exceeds what you may save in energy costs and many LED lights are relatively new in the market while HID have been reliable go to for indoor growers since the 1990’s.
HID lights produce great light coverage and penetration at a lower cost and are quite easy to set up and operate, but will require more energy for cooling and more attention to make sure your plants are getting too much light.
To answer the question, you’ll need to consider how much you’re willing to invest in your lighting system and energy costs, and how much technical know-how you have at your disposal.
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