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.
The faithful standby for old-school indoor growers, there are multiple fluorescent lighting options from which to choose.
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.
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.
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.
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.
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.
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.
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.
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. Unfort
“Auto-Flowering” strains of cannabis have different light requirements than photoperiod strains
Do Autoflowering Plants Need a Dark Period?
However, giving a plant fewer hours of light a day will save you on electricity, and if it does help the plant grow better then that’s a bonus! Combined with the fact that it gets hot here during the day and we have extremely expensive electricity, I always put my autos on 18/6.
Light in any color spectrum will produce good growth and bud as long as you’re using cannabis grow lights and there’s enough brightness.
One of the really great things about autos is how they’re able to give you pretty impressive yields in such a short amount of time. Part of the way they accomplish this is you’re able to give the plant 18 hours of light a day to power buds, so buds get 50% more light and grow faster than they would under 12/12. By giving your autos 12/12 you’re not using them to their full advantage. That being said, if you don’t mind reduced yields they’ll grow just fine! And it can be fun to stick an extra plant in the tent and let it do its thing!
Auto-flowering varieties of marijuana don’t rely on a change in light schedule to determine when to flower. These strains (sometimes called “Lowryders” or by their species name “Ruderalis”) will finish their whole life cycle in two to three months, regardless of how much light they receive a day. See a grow journal featuring auto-flowering strains.
Yellow Light for Flowering – yellow/orange/red light (like from HPS bulbs or “soft white” colored CFLs/fluorescents) tend to produce the best growth and densest buds in the flowering stage. Their color mimics the reddish light from the autumn sun. It is completely okay to give your plant yellow light for its whole life. In fact, that’s what I prefer to do as yellowish light encourages stretchy growth, and I want an auto-flowering plant that grows fast!
Additionally, the wild ancestor of auto-flowering plants (“Ruderalis” hemp) grows in the northern parts of Russia and may naturally experience nearly 24 hours of light a day in the summer. So it’s not crazy to think that auto-flowering strains will also do well on 24 hours light/day.
Short Answer: 18/6 Schedule
18 Hours Light, 6 Hours Dark (perfect for beginners)
Most strains of marijuana rely on the amount of light, or their light schedule, to determine when to start flowering. "Auto-Flowering" varieties of cannabis have different light requirements…