How To Position Your CFL Grow Lights For Amazing Results!

burned leaf

When “growing on the cheap,” DISTANCE is your worst enemy.

Distance of your light to your plants.As seen by countless unsuspecting growers who learned the “hard way,” the distance of the light from your plant(s) will make or break your grow.

Here’s a primer to help you avoid issues with your compact fluorescent grow:



  • Keep the lights too close and your leaves and/or buds will fry quicker than French.
  • Keep the light too far and your plants will stretch and become lanky; bud growth will really suffer.
  • Use lots of lights spread apart and you’ll get “typical CFL-quality” flowers.
  • Use a large-wattage CFL bulb one foot or further and expect “typical CFL” results.


So it seems as if energy-saving grows such as ours are difficult to nail, but the fact is, the truth is the exact opposite. Follow these general rules related to the placement of your lighting, whether it’s a retail-purchased reflector, a DIY reflector or hood, one lamp, a set of lamps, a socket plugged into a surge protector or more.

You will know exactly how far to place your CFL lamps when growing your Cannabis plants.


1.) Remember the “1-2 rule”

Keep the bottom surface area of your bulbs at LEAST 1 to 2 inches from the top of the plants’ foliage. Watch for heat stress, often indicated by the leaves pointing downward, away from the light, or discoloration of the leaves and leaf edges.


2.) Arrange your bulbs for max intensity,  not coverage.

Don’t make the unfortunate mistake of spreading numerous bulbs over a large surface area; you are essentially directing light to areas where the plant may not be able to use it. For instance, Sarah, a new grower, decided to make a CFL reflector using a large piece of plywood and multiple outlets.

She ended up with a 3 feet wide reflector with bulbs paired in two, spaced 6 inches apart. So, her reflector contains 12 23-watt bulbs, for a total of 276 watts shining in on her one plant–just 1 inch away! Great for her huh?

Not at all. Her plant takes up about 1.5 square feet, so she’s wasting 1.5 square feet, and 6 bulbs (138 watts) are shining nowhere near her plant. She should’ve arrange the bulbs for max INTENSITY instead of coverage, by bundling the bulbs as close together as possible, instead of spreading them out “too thin.”


3.) Use a CFL hood or reflector(s), ABOVE your plants

Above the plants is exactly where you want the majority of your lighting, since this duplicates the natural position of the sun. Additionally, you can better control the grow in smaller spaces with max light being emitted from above. For this reason, CFL growers often need to “train” their plants so they grow with a more horizontal profile, as opposed to a typical Christmas tree shape. This allows more foliage to absorb even amounts of light.

Need help learning how to build a pro-quality CFL grow light that will give your plants the perfect set up at the lowest possible price? Check out the “DIY’ers Guide to Building a CFL Grow Light!”


4.) Use less-intense side lighting to compliment “overhead lighting”

Side lighting isn’t a necessity, but it helps you get uniform growth–resinous, dense buds–on the lower parts of the plant as well as the top parts closet to the light. Using supplemental lighting to infuse the dark parts of your grow area without adding too much heat will only help to enhance the results of your harvest. As long as all parts of your plant appear to be EQUALLY illuminated, you are good-to-go.


5.) Place cool bulbs closer to foliage; warmer bulbs further away 

ALWAYS remember to place your higher wattage bulbs further away from the flowers and foliage than your lower wattage bulbs. I personally place my 23-watt bulbs close to the top of foliage in my two grow hoods, and the 40 watt bulbs are positioned at the top of the reflector close to the exhaust fans. This allows less heat stress to the foliage close to the light, but also helps to minimize the incident and temperatures of heat pockets, which can create adverse effects in your plants and retard bud growth.


By Robert Narley