It can be difficult, especially for new growers, to decide on the right kind of lighting for your grow, yet it is one of the most important decisions you can make. With dozens of lighting options available, each with their own positives and negatives, it can be a daunting task to find the lights that suit your individual needs.

Here are the 3 most commonly used lighting options to consider:

1. Compact Fluorescent Lighting (CFL)

Fluorescent lighting is the cheapest, and most versatile lighting. This is a great option for beginners, as well as for propagation, and smaller vegetative plants. They are a highly efficient source of light, and emit very little heat as a result. This means that they can be placed at a closer distance to the top of the plant canopy, and will not require as much ventilation to keep the grow room cool.

The downsides of CFL however is that they do not emit that much power. They require many lights to be used side by side, and must be placed fairly close to the top of the plants (10-15 cm) in order to provide sufficient light energy to drive the photosynthesis in the leaves. For larger, energy hungry flowering plants this is not the best option as the more intense HID lights, or the more efficient LED lighting would be a far better option. For smaller plants, seedlings, or clones however this is a perfect choice of lighting.

There are larger, more powerful CFL lights available as well, such as the 250W versions, which can be used for much larger and more light-hungry plants. They offer a cheaper option to the more expensive HID and LED lighting, but are simply not going to offer the same light intensity as these other lighting options.

CFLs also come in 2 general spectrums. Warm CFLs fall into the 6000 K range, and cool are around the 3000 K range. This means that to help initiate flowering, warm CFL lighting can be used, and cool CFL lights are the preferred option for young seedlings, clones, or vegetative plants.

The positives of CFLs

  • Very cost effective
  • Does not emit much heat at all
  • Perfect for small grow spaces
  • Comes in both red and blue spectrums
  • Very long lifespan

The negatives of CFLs

  • Does not provide high intensity light

2. High intensity discharge (HID)

HID lights are the bread and butter of indoor growing. They emit a massive amount of light energy and come in a variety of different spectrums. They use a controlled electricalal arc and the interaction of gas contained within the bulbs to emit a powerful glow.

In order to maintain this arc, an electrical ballast is needed to control the flow of electricity. The main HID lamps available are metal halide (MH) and high-pressure sodium (HPS). In most cases, either one can be used effectively, however for many flowering crops, a combination of the 2 are used.

MH lights emit a spectrum in the 4000-6000 K range. This is considered a cool or blue spectrum and is much more suited towards plants in the vegetative stage of life. Bluer lights mimic the spring and summer months, and tell the plant to continue vegetative growth. It also promotes thicker root and shoot growth and prevents the plants stem from stretching or growing upwards too fast and eventually flopping over.

HPS lighting emits more of a red spectrum, somewhere in the 3500 K range depending on the manufacturer. This spectrum makes HPS lighting perfect for plants in the flowering stage of life, and mimics the autumn. This tells the plants to begin flowering and developing fruit, and can cause the stems to grow taller faster in an attempt to reach the flowers as high up as possible.

MH and HPS are generally used in combination due to their different spectrums, which are optimized for different stages of life. MH is used for the vegetative stage and is swapped over to an HPS bulb during the flowering cycle along with a light cycle change.

The problem with HID lighting is that they have a higher investment cost than CFLs and emit much more heat. Ventilation must be used with HID lighting in order to remove this excess heat and prevent it from building up inside the grow room. See our extraction calculator here.

Anybody serious about indoor growing should consider using HID or LED lighting in order to get the most out of their plants.

The positives of HID lighting

  • Emits a high light intensity to drive photosynthesis
  • Comes in both red and blue light spectrums
  • Can be used as a source of heat for cooler grow rooms or tents
  • Cheaper than LED lighting

The negatives of HID lighting

  • Releases a large amount of heat, which can be problematic if not ventilated or cooled adequately
  • More expensive than CFL lighting
  • Short lifespan (6-12 months/bulb)

3. Light emitting diodes (LED)

LED lighting is fairly new to the plant cultivation scene. Only in the past 6-7 years has it really been developed as a means of growing plants. Since this time there has been a ton of research optimizing these sources of lights to cultivate plants.

The cool thing with LEDs is that the spectrum they emit is fully customizable. There is no limit as to what color spectrum an LED can be designed to emit. It uses hundreds, or thousands of highly efficient LED lights into one larger light system. They release nearly no heat, and the LEDs themselves last for decades without losing any of their efficiency.

LEDs are by far the most expensive lighting up front but pay themselves off in the long run with their incredibly long working life, low energy costs, and the high yields they can produce.

LEDs come in all kinds of spectrums, and due to the design they can even be built to give off a very specific colors and spectrums. You will often find LEDs coming in colors such as magenta, blues, reds, purples, or a combination of these. Depending on the life stage of your plants will determine the best spectrum to use.

The world of LED lighting is new and exciting and offers a means of growing plants with minimal energy and maintenance costs.

The positives of LED lighting

  • Very long working life (over 20 years with only ~20% efficiency reduction)
  • No limit on the varieties of spectrums available
  • Emits very little heat
  • Can be used in small grow rooms or tents
  • Suitable for all stages of plant development

The negatives of LED lighting

  • High initial investment cost

Tieing it all together

Choosing the best light source is tough for new growers. When you take into account all of the different light sources available, and consider their positives and negatives it can get a little easier. Is your grow room small and have minimal ventilation? Try CFL or LED. Do you have a large grow room with many plants, good ventilation and a lot of startup investment? Go for a combination of MH and HPS or LED.

Everybody's situation is different, but no matter what your setup is like, one or more of these lights is right for you.

Feel free to ask one of our experts about what lighting may be the best option for your grow here.