The Best Lighting for Autoflower Cannabis

If you're growing indoors you'll need to provide your own light, but which option is the best? HID, LED, CFL? We break down all the lingo so you can focus on growing.
Author Ryan
12 July 2018
3 min read
The Best Lighting for Autoflower Cannabis

  • 1. Fluorescent lights
  • 1. a. Cfl
  • 1. b. T5
  • 2. Hid
  • 2. a. Metal halide
  • 2. b. Hps
  • 3. Leds
  • 3. a. Cobs
  • 4. What's best for you?

There's something genuinely satisfying about planting a seed in the ground and watching a cannabis plant seemingly appear out of nowhere, fed by the sun. Unfortunately, prohibition prevents many growers from doing just that. They have to take their growing indoors, away from the light source these plants were designed to use. Indoors growers have to pay for every lumen of light, and replicating the sun doesn't come cheap. Thankfully, lighting solutions for cannabis growing have come a long way in the past ten years. Before, even the smallest growing operation would use as much power as an air conditioner or over-powered gaming PC, whereas today it's possible to grow weed with bulbs that use less energy than the lights in your kitchen.

We covered each different kind of bulbs available in our article, How to Grow Autolfower Cannabis Indoors. Head on over there for a breakdown of the technology. Today we're going to identify your needs and pick the best solution. Here's a quick run-down of the options.

Fluorescent lights

The faithful standby for old-school indoor growers, there are multiple fluorescent lighting options from which to choose.


CFL Bulbs

CFLs are those twisty bulbs you probably already have in your home. They can be found in any hardware store. Their ubiquity makes them an ideal solution for a discreet grower who doesn't want cultivation supplies on his or her credit card statement. Their only downside is that while each bulb has relatively low power consumption, you'll need several bulbs to provide enough light to grow ganja. Power consumption might reach over 400 watts to generate enough illumination.


T5 Lights

T5s are what you probably picture in your head when you hear the word fluorescent. These long tubes of electrically charged gas have been around since the 1930s. Cannabis responds better to the T5 light spectrum than CFL's, and they're powerful enough to grow a plant from seedling to harvest. They're a bit more conspicuous than CFLs, but it's not unheard of for people to have homes lit by T5 lights, especially in East Asia.


HID bulbs blast out massive amounts of light, and you'll notice it in your plant's growth if you decide to use them. They utilize the perfect spectrum for cannabis cultivation, but they also generate large amounts of heat and use a great deal more electricity than other options.

Metal Halide

Metal Halide Bulb

Rarely used for the length of a full grow, metal halide lights provide the ideal blue spectrum for vegging cannabis plants, but many growers switch to HPS come flowering.


HPS Bulb

After vegging under metal halide, growers will often switch to high-pressure sodium lights for flowering. In terms of electricity used per unit of energy for the cannabis plant, the MH/HPS combo is the best option. However, neither of these lights come cheap, and while they may be efficient in relative terms, they still use a great deal of power in the process, and you'll see it on your electric bill.


Fast Buds Tangie'Matic Under LEDs

LEDs are the perfect low power solution for growers with smaller tents and those growing with discretion in mind. Their low power usage means you'll barely see an uptick on your electricity bill, at least if you're only using one or two lights.

Traditional LEDs are giant arrays of bluish-purple lights that looks like something from a science fiction movie. Their not as efficient as HID bulbs, but their low power consumption more than makes up for this fact. The biggest downside is that the purple light wreaks havoc on cameras, meaning you'll have to turn them off to get beautiful pictures of your hard work.


A COB Light

Chip on Board lights are tiny LEDs that put out an intense white light. A single 100w cob light is enough to power a small grow tent by itself and will only run you $100. If you're looking to grow on the cheap, COBs are even better than CFLs regarding power consumption and just slightly more expensive at retail.

What's Best For You?

That's a quick summary of your options, so what's the Best Lighting? It depends on what you value.

If you want to save on start-up costs: Four to six CFL bulbs are your cheapest option, but you'll pay for it in power consumption later.

If you want to save on electricity: A 100-watt cob light will use the same amount of energy as a single old-school incandescent bulb would have. If you don't want to see your energy costs increase, COBs are your best option.

If you want the largest yield: For yield, HID can't be beaten. While you'll pay a pretty penny to procure and run them, they're the only option that can come close to competing with the sun. HIDs will produce more grams of cannabis produced per watt of electricity used than any other option.

Author Ryan
12 July 2018