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Which Grow Lights Are Best for Growing Cannabis Indoors?

Light is the energy source for all life. So if you're interested in growing cannabis, light is one of the most crucial aspects of the growing process, so deciding on the proper lighting setup is very important. Cannabis requires different light conditions during the various stages of its growth -- the vegetative phase and flowering phase. We'll look at what the different light options are for growing cannabis and how suitable each one may be for your setup while we weigh the pros and cons of each type.

Cannabis Light Requirements

Cannabis (and all plants), require a Photosynthetically Active Radiation (PAR) in the spectral range of light from about 420 to 750 nanometers. Without it, photosynthesis cannot occur, meaning that your cannabis plants will not grow. There are many different types of grow lights that can be used to grow cannabis indoors, such as:

  • Metal Halide Bulbs
  • CFL lights
  • HPS lights
  • Fluorescent lights
  • LED grow lights

1. Fluorescent Lights

The use of fluorescent lights in growing cannabis indoors is rather common. This may be attributed to the fact that these lights offer pleasant and efficient lighting. Available in a myriad of sizes and shapes, fluorescent lights are great when used for growing herbs indoors. These lights may be grouped into two:

· CFL Lights

Compact fluorescent (CFL) bulbs are a common type of fluorescent lights that may purchased from almost any store that sells light bulbs. When used to grow cannabis indoor, cfc lights are ideal for comparatively tight spaces like within a cabinet.

· T5 Grow lights

T5 grow lights are another type of fluorescent light that is commonly used to grow this herb indoors. These may be purchased from almost any home improvement or garden store. As compared to CFC lights, these are a bit larger and are often availed as a part of a panel. When using T5 lights, it is advisable to keep the light source a few inches above the herbs to avoid burning them. 

Pros of Fluorescent Grow Lights

  • Efficient on energy
  • Comparatively affordable
  • Ideal for use within tight spaces
  • Offer the right light spectrum for growing cannabis indoor

Cons of Fluorescent Grow Lights

  • Have a relatively low yield per watt
  • Light from fluorescent sources does not penetrate throughout the plants, hence is only ideal for plants trained to grow flat and short. 

2. LED Grow Lights

LED grow lights are commonly used as an alternative to hps lights in growing cannabis indoor. These lights are ideal for growing cannabis indoor because they have a great penetration. They are also convenient to use as you only need to hung the light above the herbs and plug it to a power source.

Pros of LED Lights for Indoor Cannabis Growing

· Smaller varieties of LED grow lights may be plugged in and hung over the plants hence are convenient to use.

· LED lights for growing cannabis indoor often have cooling systems. This system draws heat from the herbs allowing you to grow cannabis indoors without the need for ventilation.

· These grow lights are believed to produce more resinous bud.


As compared to hps grow lights, LEDs are associated with lower yields per wattage of about 0.5g/watt.

· While most LED grow lights run cool, they still produce some heat. As such, the larger LEDs like 300W+ may require ventilation.

· LED grow lights require a relatively larger space between them and the herbs. As such, they have to be used in larger spaces, for best results.


3. HID Grow Lights

High intensity discharge (HID) lights for growing cannabis indoor are available in various types. These lights are often powered by big bulbs of odd shapes. As compared to fluorescent grow lights, HID lights are more efficient. These grow lights are normally screwed into reflectors that bounce the light back to the herbs. HID bulbs produce a lot of heat and should be connected to an exhaust to vent the heat. Some of the HID grow lights used to grow cannabis indoor include:

· High Pressure Sodium (HPS) lights

Light produced by the HPS lights appears to be yellow, hence is ideal for the flowering stage of cannabis. The light spectrum produced by this grow light stimulates the production of buds in this herb. When used during the flowering phase of cannabis, HPS grow lights are more efficient than any other type of grow light because they have a relatively high yield per wattage. 

· Metal Halide (MH) Lights

Metal halide bulbs are commonly used during the vegetative phase of cannabis. The bluefish light produced by MH grow bulbs makes them appropriate for illuminating cannabis during the vegetative stage. However, you may also use the light for all the phases of cannabis growth.

· Light Emitting Ceramic (LEC) and Ceramic Metal Halide (CMH) Cannabis Grow Lights

While some sources may use the two names differently, they all refer to the same type of grow lights. Similar to the HPS grow lights, this metal halide bulb features ceramic as a part of the entire lamp. This makes the CMH bulb more efficient, as compared to the conventional MH lights, but not as efficient as the HPS grow lights are.

Benefits Associated with HID Grow Lights

· Basically, the HID grow lights are the most efficient type of grow lights today.

· They are easy and convenient to use because they may be plugged to a power source and hung above the herbs.

· The efficiency of these grow lights makes them ideal for the flowering stage of cannabis. When used this way, these lights have a yield of about 0.5 to 1 gram per watt.


· Since the bulbs produce a considerable amount of heat, they require additional setup to vent the heat.

· They have more lamp parts than any other type of grow lights.

With so many types and models of grow lights to choose from today, buying the appropriate light for growing cannabis indoor can be a bit challenging. When shopping for grow light for cannabis, it is advisable to get one that offers white or green light (what is considered to be full light spectrum). Again, you should avoid lights that feature diodes for blue and red light. Growing your cannabis with the later type of light may lead to nutrient deficiencies, hence low yields.

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