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best lumens for growing weed

Many growers first starting out tend to get confused between watts and lumens. Watts are the amount of energy a bulb consumes. Even if a bulb has a high wattage, it does not necessarily mean that it will produce high lumens. This is especially true with new high-energy LED lights because the amount of wattage does not guarantee a brighter light.

Most standard fluorescent tubes produce 3,000 to 3,300 lumens per tube. There are various tricks that a cannabis grower can do to increase the lumens of a grow light, such as placing a metal or foil reflector behind the bulb or tube to reflect even more light down onto the plant. This trick increases the amount of lumens generated by the light source that reach the plants.

Ideally, a marijuana plant should have 4,500 lumens to ensure maximum growth. A 4,500-lumen bulb will cover a 3×3-foot space with adequate lighting.

Cannabis plants are dependent upon precise light/dark ratios in order to adequately flower and produce an ample harvest. Growers must ensure that the plants receive sufficient light so the plant can complete its life cycle.

Maximum Yield Explains Lumens (lm)

A common expression in the cannabis cultivation community is "lumens are for humans, PAR is for plants." This is a way of saying that for grow lights, growers should be most concerned with how much photosynthetically active radiation (PAR) a plant puts off, rather than it's level of lumens.

Lumens are the amount of light a bulb provides. Essentially, lumens mean brightness. The higher the amount of lumens, the brighter the light that will be achieved. Plants, especially cannabis plants, require adequate light to grow. Typically, one cannabis plant needs at least 2,500 to 3,000 lumens.

Plants need adequate light in the blue and red spectrums, which is considered the PAR range. Lumens is a good place to start, but PAR levels will take your consideration of grow lights to another level. Make sure your grow lights have the right level of lumens in the right PAR range.

Best lumens for growing weed

Deciding on light setups for any indoor garden can be a daunting task. The horticultural lighting industry almost feels like it is purposefully trying to confuse us sometimes, possibly in the hopes of getting consumers to purchase more items—or more expensive items—than we really need.

Greetings to you, Nico!
I have searched the web and noticed that you are the guy to ask about indoor lighting for cannabis horticulture. My question is rather simple, I think: In terms of lumens, what light output do I need to grow a plant or two successfully in my home? I have a small bedroom and am thinking of using a ’ x 4’ or 4’ x 8’ grow tent? Any suggestions on bulb types and strength would be helpful! Many thanks & good luck to you! — Jonathan V. via the mailbag at [email protected]

This 4′ x 8′ grow tent uses two 1,000-watt HPS bulbs, but must air cool the lamps to keep temps down. (Photo by Nico Escondido)

Still, even with a more scientific view, it appears that a 1,000-watt HPS would be plenty sufficient to light a 4’ x4’ tent—or just 16 square feet. However, there is still another factor often not considered when choosing the correct lamp: heat byproduct.