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Grow Lighting

When building an ideal indoor grow environment, the goal is to replicate sunlight utilizing grow lighting equipment. Surprisingly, technology has come quite far in allowing us to mimic the photosynthesis process typically provided by the sun. However, not all artificial lighting systems are created equal.

Types of Grow Lights

Regardless of which type of grow light you choose, none are truly comparable to a sunny day. Indoor lighting is, however, a fantastic way to extend your growing season.

Below you will find the various options available to you, as well as their benefits and pitfalls. We hope this helps you in your journey to building to perfect grow room setup.

T5 lighting system


Fluorescent lights are a long-time favorite of indoor home gardeners. However, most cannabis growers will only use these to keep clones under for short periods of time. 

Most fluorescent bulbs only produce a limited range of light, which typically doesn’t allow for plant flowering. However, some of the newest “T5 Lighting Systems” produce a wider light spectrum for all-purpose use!

Generally, fluorescent lights are best suited for germination and vegetative growth. Many favor fluorescent lights because they have a lower risk of heat damage to plants. However, these lights are nearly obsolete as technology has shifted.

High-Intensity Discharge (HID) Lamps

High-Intensity Discharge (HID) lights are some of the best options on the market. 

HID Lights come in four types:

  • High-Pressure Sodium (HPS),
  • Metal Halide (MH),
  • Low-Pressure Sodium,
  • and Mercury Vapor.

However, only two of these apply to indoor growing: Metal Halide (MH) and High-Pressure Sodium (HPS).

Both of these types typically come in two sizes of:

  • 600 watt: recommended for an area of approximately 16 sq. ft.
  • 1000 watt: recommended for an area of approximately 25 sq. ft.

For the fastest growth, it is recommended to use approximately 40 watts of HID light per square foot of garden.

Metal Halides

Metal Halide bulbs produce light on the blue spectrum, which enhances growth but is not the best for plant flowering.

Metal Halide lamps will provide optimal blue-white color for approximately 10,000 hours – the lamp will likely still provide light beyond 10,000 hours –  but the quality of the light will be diminished so it is recommended to replace the lamp at this time.

MH bulbs provide an excellent primary light source which will help keep plants compact while still promoting leafy growth.

Along with Metal Halide, a High-Pressure Sodium (HPS) light may be a good addition to your indoor garden, as the red-orange light produced by these bulbs is much more effective than MH at producing buds and flowers.

As a note, an HPS lamp also has roughly twice the lifespan of an MH lamp.

When discussing HID lighting, the ideal solution is to invest in both metal halide and high-pressure sodium bulbs and to use both in tandem. The MH lights will be used first, to promote leafy growth – then the HPS lights can be swapped in to encourage plants to flower.

Ceramic Metal Halide (CMH)

Ceramic Metal Halides are a newer form of lighting that is much closer to the spectrum of the sun compared to HID lights. For this reason, many growers are opting to use them. The most standard CMH fixture is the 315w unit. Some growers don’t find these adequate for flower which has led to manufacturers creating more powerful units.

Most recently, double-ended 630w units and 1000w units have hit the market. These are able to provide the quality and yield most growers are looking to achieve and are highly recommend when starting a new grow or when looking to upgrade.

Light Emitting Diode (LED)

Light Emitting Diode (LED) lights are the newest technology on the market for indoor grow lights. The bonus of these lamps is that they create very little heat. Therefore, eliminating the risk of plant and property damage or personal injury.

In addition to this, they are also the most energy-efficient type of lighting available. LED lights are often programmable, and can most-closely replicate not only the temperature of sunlight but also both the red and blue color band spectrums needed for vegetative growth and flowering. Most LED lights now emit a white light which is considered a full spectrum, closest to the sun. However, LED grow lights are currently the most costly lighting option, but prices are expected to fall as this new technology ages.

How to Measure Lighting Costs

Measuring kilowatts hours is the method used to determine the efficiency of the plant’s yield. Regardless of what type of lighting system you choose, this is the formula for computing operational costs:

  1. Begin by taking the combined wattage of all the lights you will use and divide it by 1,000 to get the kilowatts used.
  2. Multiply the kilowatts figure by the amount your electric company charges per kilowatt-hour (kWh).
  3. Once you get the operating cost per hour, you can multiply that by hours used per month to get your monthly operational costs.

To learn more about the lighting schedule cannabis follows from start to finish, check out our comprehensive cannabis grow guide here.

We really hope this has helped you consider all of your lighting options prior to making your final decisions and as always, if you have any questions, please leave them in the comments below and we will respond as soon as possible.

Happy Growing!