Long gone are the days when growing weed at home means ridiculously high electric bills.
For the closet grower, cultivating only a couple plants at a time, a thousand-watt high pressure sodium light is overkill.
While high intensity lights generally produce better yields, with proper care you can produce high yield harvests using Compact Fluorescent Lights, or CFLs.
This guide will show you what to look for when using CFL grow lights.
Watts Vs Lumens
Since the goal is to reproduce the effect of direct sunlight on the plants, you would think the higher the wattage the better. However, with CFLs this is not necessarily the case.
Watts are the measure of energy used to produce light. Lumens measure the light produced.
Paying attention to the lumen/watt ratio can save you big money. Just divide the lumens by the wattage (lumens/watt) to determine the efficiency level.
So, for example, a 200 watt CFL outputs 9,250 lumens, which has a ratio (9250/200) of 46.25%
On the other hand, a 23 watt bulb outputs 1,600 lumens. With a ratio of nearly 70%, the 23 watt is much more efficient.
Be sure to check the ratio yourself before buying since there are differences between manufacturers.
Not all lights produce the same light spectrum–even white lights.
By paying attention to the Kelvin scale on the package, you can determine which spectrum of light the bulb emits.
Weed plants need a blend of blue spectrum and red-yellow spectrum light to encourage proper growth.
Warm white bulbs offer the red-yellow spectrum of light, which is ideal for the fruiting stage. On the box, the lights
Cool white bulbs produce more blue spectrum light and are good for the vegetative state. On the box these lights will have a higher Kelvin rating (usually around 6500K).
Experiment with different combinations of cool and warm lights during different stages of your grow to see what works best for you.
Light Placement and Intensity
The most important thing to remember is to have enough light for your space and to place your lights where they will saturate your plants the most.
Since CFLs produce significantly less heat than high intensity lights, it is possible to keep your lights closer to your plants, giving them increased light absorption potential. But still keep your lights high enough above your plants.
For most closet growers, four or five 23-watt bulbs are sufficient. Be sure to use mylar on the walls and floor of your grow room to maximize your light use.