What Type of Lights is Best for Growing Cannabis Indoors?

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The light you shine on your cannabis grow makes or breaks your product. Cannabis needs light that surrounds and embeds infiltrates the tangle of leaves, hairs, and buds. Cannabis wants light from above and below. The plant’s peculiar botany responds to different parts of the light spectrum at different stages of growth. So, you want to light your cannabis well.

There are two areas of sensitivity. The light during the sprouting stage cannot issue the heat that would burn the seedlings. And, the plants at flowering stage need a more intense light that you need to cool. So, if you plan on growing indoors, you must consider your budget, your commitment, and your learning curve.

Start with this survey of fluorescent, HID, and LED approaches:

Here’s the deal with fluorescent grow lights:

  • Cheap: If you’re only growing one or two plants or if you’re on a budget, fluorescent lights sell cheap. For small grows, their lower efficiency doesn’t make much difference.
  • Low Power: Fluorescents do not produce much power, so you can’t count on them to maximize yields during flowering. But, they are more than enough when you're only in a cloning or vegging phase.
  • Low Heat: Because fluorescent put out less heat, you can hang them close to your plants without damage. That makes them perfect for a cloning nursery or compact grow room.
  • Blue Light: Fluorescent bulbs supplement other lighting systems with a blue-spectrum light.

Here are the top five fluorescents:

  1. Hydro Crunch 4′ T5 Fluorescent Light System comes with a 95% highly effective aluminum reflector to maximize light output. This system includes eight 6400K bulbs at 54-watts each. Perfect for vegetative phase and plant propagation. The 40,000 blue spectrum lumens can hang horizontally or vertically at 46.25"L x 24"W x 2.4"H. Sleek, white, and self-contained, this fixture works for any garden, including hydroponics.
  2. Hydrofarm’s Agrobrite FLT44 T5 Fluorescent Grow Light System comes with four high-performing 6400K T5 Tubes. The power-coated steel housing hangs at 3"H x 13.5"W x 46"L. The premium grade specular aluminum effectively doubles the output. Rated between 18,000 and 20,000 lumens, the tubes light plants where they need light. The fixture also come at a 2-foot length or wide enough for 12 tubes.
  3. Power T5 Fluorescent 4-Foot Tube packs bulbs rated for 6,400k color temperature for starting or sprouting plants. But, you can replace with 3,000k bulbs for a warmer light for flowering. The reflector directs 95% of the grow light back on your plants. Dual on/off switches control the lighting fixture through two banks of lighting. At 2.5"H x 11"W x 48"L, it’s the right size for most small grow spaces, but you can daisy-chain as many as 10 fixtures off one outlet
  4. DoroLux T5 DL844S Grow Light is bargain-priced for a high-quality fluorescent system rated for safety in wet and dry environments. The 47.5"L x 12.5"W x 4"H fixture holds four 4-foot tubes in a 95% reflectivity German Hammer-tone reflector. At 20,000 lumens, the output is high, but you can still place the lamp two to three inches from the plants. It works with timers, and a switch turns two of the four bulbs on and off independently.
  5. AgroBrite FLT24 T5 Fluorescent Grow System is a small but full fluorescent light system at an affordable price. It hangs vertically, horizontally, or overhead. At 3"H x 13.5"W x 23"L, the fixture comes with four 6400K T5 Tubes enough to produce 8,000 lumens. Its powder-coated, steel housing and high performance faceted aluminum for distributes light fully. You can link systems in series or upgrade to 4-foot tubes.

Here’s the deal with HID grow lights

  • Cheaper: The complete HID system comes in more affordable than LED fixtures, but the real savings come from energy efficiency
  • More heat: HID systems produce a lot of heat with HPS (high-pressure sodium) and MH (metal halide) bulbs. You must distribute and exhaust the heat or harm the plants.
  • Big yield: HID lighting still produces the highest yields, but tests find more potency in products grown under LED lights.
  • Two bulbs: MH blue-spectrum bulbs are perfect for early-stage growth, but you must switch to red/yellow-spectrum HPS for the flowering phase.

Here are the top five HID grow lights:

  1. Sun System LEC 315 Indoor Grow Light Fixture is engineered for agricultural use. A single cutting-edge LEC (Light Emitting Ceramic) agro lamp inserts into a 98% reflective German aluminum insert and 95% textured reflective corners. A full-color, far-red spectrum improves growth and yield potential. And, long life and high efficiency reduce the hefty cost.
  2. TopoLite 315W CMH Grow Kit is an industrial looking fixture. Its single bulb produces a strong light with high temperatures you need to monitor. The full-spectrum light works for vegetative through flowering stages. This small fixture lights a 4 square foot area at a moderate price.
  3. Apollo Horticulture Dimmable HID System may be the easiest way to go for new growers through the full growth cycle. It comes with one HPS bulb and one MH bulb under an air-cooled 24"L x 17"W x 9"H fixture of galvanized steel and German aluminum.  A 24-hour timer programs your lighting cycle.
  4. Ushio 1000W Dual Arc Tube seems pricey for one bulb. But, this dual arc lamp gives consistent full-spectrum light for your plant’s entire life. German engineering focused on high performance, optimized spectrum, lumen output, and distribution pattern. And, experienced growers credit it with producing super trichome growth.
  5. Hortilux Eye Dual Arc Bulb combines the MH blue and HPS red for a single growth cycle light source and beats switching out bulbs. The 1000-watt, 3000K, 110,000 lumens and 10,000 hours of life can offset its significant price.

Here’s the deal with LED grow lights

  • Pricey: High-quality LED lighting fixtures cost more than HID systems.
  • Less power: LED lights can maximize your operating costs because they use much less power and generate far less heat.
  • Low heat: LED lights are cooler than others, so you need less cooling equipment.
  • Easy use: It’s a place to start because, if your experience is with HID, you will be learning all over again.

Here are the top five LED grow lights:

  1. Diamond Series XMLs covers 4.5 square feet from 18-inches high, so it’s perfect for grow closets or tents and up to six plants. The 11+ spectrum light nourishes plants and responds to two switches marked “Veg” and “Bloom.” The panel holds replaceable modules.
  2. Galazyhydro’ Roleadro Series 300W is a full spectrum lamp with light wavelengths to cover the photosynthetic dynamic radiation zone (PAR). The light is crafted to imitate the sun’s light. And, it comes with a dimmable component to enable better control of the light force to adjust the light effect without adjusting the lamp height.
  3.  VIPARSPECTRA Reflector-Series 300W limits the grow area to 2 square feet, but it offers exceptional PAR esteems. The PAR esteems decrease if you widen the area to 3’ X 3,’ another way to control the light as the plants mature.
  4. G8LED 900W MEGA LED has a whopping thousand dollar-plus price tag, but many reviewers put this award winner at the top of their lists. Durable and energy efficient, it can save you money if you are into growing for the long term. Made in the USA, this 900W Veg and Flower light covers 24 square feet with high PAR esteems. 
  5. California Lightworks 440W LED Grow Light is another pricey entry. The bright red fixture distributes an intense light from 88-5W LEDs. There are added 2-15-watt UV-B T8 tubes. Yet, it runs cool with its built-in circulating fans.

The final issue

Price is a real issue in how you plan to go. If you are trying to hide your crop in a closet or small grow tent, you must consider light, heat, and circulation. But, space and budget will rule. If you have more room, you want to purchase and place your lighting strategically, and that should justify a larger investment.

So, it comes down to what return on investment you are after, a modest homegrown stash or a nicely performing indoor farm?