CFL Grow Lights - Beginner's Guide

There are many concepts to get your head around when you start out in hydroponics. By far the most complex is lighting.
It is crucial to learn about the many different types of lights for indoor growing. Then you have to digest the properties of light itself - and understand how plants use it to grow.
The most basic and cheapest type of light available is the compact fluorescent light bulb, or CFL. They are a very good starting point, not least because they're easy to find, cheap to buy and do a good job assisting the growth of a variety of plants.

CFLs in a Nutshell

CFLs were developed as replacements for classic incandescent lamps.

Incandescent bulbs are those electric lights with wire filaments that heat to such a high temperature they glow with a visible light called incandescence.  Although they are undoubtedly amazing and changed the history of mankind, the simple fact is they burn hotter and waste a lot of the electricity used to power them. Indeed 90% of their energy is heat and just 10% is light.

CFLs, on the other hand, last up to ten times longer while putting out much less heat. They are also more efficient because they extract less wattage to deliver a similar amount of visible light as incandescent bulbs.

Reason to Use CFL Grow Lights

There are many reasons for using CFLs instead of much more expensive lights like LED grow lamps, high pressure sodium or metal halide.
They are low in cost, expend little electricity so they are cost effective to use. In addition, they can be easily obtained and are highly customizable. This is due to the fact they are supplied in a number of different shapes and sizes and a range of wattages.
No special fixtures are required and they can be installed very close to plants for maximum effect.

The Main Types of CFLs for Indoor Gardening

Compact Fluorescent Lights (CFLs) are a recent innovation in the world of indoor growing. They are energy-saving lights, which come with integrated electronic controls.
These Cultilite Lights can be employed as either a primary grow light or as supplementary to whatever light you choose as your main one.

Very compact, they are particularly useful in that they generate such little heat. This means:
1. they will not dry out your soil
2. can be placed as close to the plants as possible. This will result in higher yields.


For the flowering stage the Cultilite lights radiate a spectrum which stimulates the photosynthesis process. 

CFL lights are different color temperature. Measured in degrees of Kelvin (K) on a scale from 2100  to 9.500, color temperature is important because it is the characteristic that defines the different temperatures of light that plants need for different phases of their growth.

Here is the CFL models available
CFL Grow Lights 2100°K - Orange/Blue Color Spectrum (Full Cycle)
CFL Grow Lights 6500°K - White Color Spectrum (Growth Stage)
CFL Grow Lights 2700°K - Red Color Spectrum (Blooming Stage)

Growth bulbs, which are measured between 9500K and 6500K, are the top of the tree when it comes to the phase of plant growth known as "vegetative".  This is when plants put out an abundance of leaves and grow rapidly as they anticipate the flowering phase.

The Bulbs

Cultilite bulbs and their associated lighting fixtures are the best choice for a plant's grow phases and can be placed close to your plants because they don't generate as much heat as other types of bulbs. This means your plants won't burn. Nor will the stems stretch out as they reach for the light. This weakens the health of plants.

Cool White, Light Blue bulbs, which are measured between 9500K and -6500K, are considered optimal for the vegetative phase of a plant's life.

Warm White, Light Orange, which are measured between 2700K and 3000K, are the best for a plant's flowering phase.  They give off a warm light that mimics the power of the sun's rays when most plants have burst into flower and have started spreading seed for the next generation.

DIY or Buy a Lighting Fixture?

There are two options when growing with CFLs. You can either plant separate bulbs and construct your own lighting system or you can buy a ready-made lighting fixture.
When going it on your own with separate bulbs beware that when CFLs are advertised it is both with their true wattage and an incandescent equivalent. The rule is to ignore the incandescent or replacement wattage and make your decision based on the true wattage.

One of the best  CFL bulbs is The Cultilite 150w (2700K). It's not the cheapest but it is efficient and does a good job in the flowering phase for most plants. It has just the right light intensity that will produce the flowers and the fruits you want on your plants.

One of the best Daylight CFL bulbs is the Cultilite 150w (6400K). This is a good, relatively cheap bulb for the vegetative phase. It is consistent in generating high-quality plant growth.

For many growers a CFL fixture makes more sense because they are already setup so there is no fiddling about connecting bunches of bulbs. This not only saves a lot of time, but it also precludes the headache, stress and frustration if doing it yourself is not your strong point. You are a grower not an electrician after all!

Bulbs or Watts? What is needed?

The rule of thumb: the more light the better.

Start at about 125 watts for each plant, though be aware that some plants need more light than this.  Indoor lettuce gardens, for example, need less light because lettuces are fast-growers with only a vegetative phase.

To decide whether more light is required in your garden, watch out for any underwhelming growth in your plant. Make sure the system you use is adequately covering all angles of your plants.
The aim is to mimic sunlight in the best way possible, so remember that sunlight moves around and covers a plant's angles with light as the day progresses.

How CFL Grow Lights Should Be Used

A major advantage of using CFLs is they plug easily into your conventional light sockets. In addition they are available in a variety of sizes and shapes so they can be customised to your requirements.

Light comes out of a bulb's every angle, so arrange your CFL bulbs so as much of each bulb is pointing at your plants as possible.
If possible keep the lights between four and six inches away from the surface of your plants.

With a significant amount of light pointing away from a plant in any lighting system, it is a good idea for gardeners to employ reflectors to harness as much of this otherwise wasted light as possible and to redirect it toward the plants.