Lighting: Is your Cannabis getting the light it needs?

If you ask around, most people will say that the best grow light is the sun. And why wouldn't the sun be the best grow light? Nature thrives that way after all, it just makes sense. Unfortunately, not everyone has the space and privacy to grow Cannabis in the great outdoors, the reality for some is that for various reasons it isn't always possible to grow you cannabis outside, safely. So if you are stuck with this problem, you will find yourself needing some indoor grow lights. This is where many growers begin to struggle, because there is so much information about the various options that nobody knows where to go or what to do. So in an attempt to solve this confusion once and for all, we have decide to go through the most common kinds of available grow light, so we can examine the pros and cons and better understand which lights suit which setups.



CFLs, which are known as compact fluorescent lights, are some of the most common you’ll see out there. You can get these lights at many places, including hardware stores and even your local Checkers or Spar. 

They are especially suited to small grows, and will be the most affordable starter lights you’ll find. Conveniently, these bulbs have standard sockets so you can use them with any standard light fixture or lamp. 

You can find CFL bulbs at 6500K or 2700k, with a more reddish light spectrum. Bulbs with a 6500k spectrum are more suitable for the vegetative growth phase, while 2700k CFLs are better for the flowering phase of the plant. 

  • CFL Cost and Expected Lifespan

A standard 20W CFL bulb will only set you back around R80. This makes them great starter lights for growers on a budget. It’s a lot of light for the tiny dent in your wallet! 

  • Yield per CFL

You should get around 0.3 grams per watt, this could potentially be higher if you switch from the 6500k to the 2700k bulbs for flower. (A 200w setup could easily net you 50 grams at a small cost of R500)

  • Pro's and Con's
    • Pro's:
    1. Widely available and very cost effective.
    2. Great for beginners.
    3. Easy to set up.
    4. Come in a massive variety of shapes/sizes/wattages.
    5. Does not get hot.
    6. Perfect for clones or seedlings.
    • Con's:
    1. Only suitable for 1 -2 plants. 
    2. Not ideal for flowering as it results in low yields.

There are two main types of HID lights for growing cannabis: MH (Metal Halide), and HPS (High Pressure Sodium) lights. The difference between the two is that MH lights produce a blue-ish light, whereas HPS lights usually tend towards the red end of the spectrum. This makes MH lights more suitable for the veg, with HPS lights being better for flowering.

Therefore, the most advanced growers use a combination of MH and HPS bulbs for the duration of the process. If, for some reason, you need to choose one type of HID for the entire grow, we would highly recommend HPS lights. 600W HPS lights are the most popular size. You can often find kits for HPS lights that come with a ballast, bulb and reflector. We would just recommend staying away from any cheap ballast/bulb. 

  • HID Light Costs and Expected Lifespan

As discussed, you can find complete HID lighting kits that include a lamp, a ballast, and a reflector for R3000 and up. The low initial cost, however, will be offset by the higher electrical consumption. (The average 600w HID lights consumes around R700 worth of power per month here in SA)

The bulb lifespan is approximately one year. In turn, you should replace your bulbs annually to maintain optimal light output. We personally replace our bulbs each and every grow. 

  • Yield per HID Light

You can expect around 0.5–1g+ per watt, which is roughly 300–600 grams/standard light.

  • Pro's and Con's
    • Pro's:
    1. Cheaper than high end LED lights.
    2. Reliable and consistent. 
    3. Lights are serviceable (A ballast can be repaired)
    4. Options for veg and flower
    5. Low initial cost
    6. Produces high yield and dense buds. 
    • Con's:
    1. HPS/MH give off high amounts of heat. 
    2. Bulbs need to be replaced often.
    3. HID's consume an exceptional amount of power. 


LED Grow Lights

Until Recently, LEDs weren't feasible for commercial grows, other than for seedlings or clones. However, LED technology has developed very quickly in recent years. Most LED grow lights give off light that is suitable for both veg and flower periods, some models offer options to alter the composition of light with a switch to alter which lights are on in order to achieve different spectrums of light (more blue for veg and more red for flower). Newer light technology such as 'Quantum boards' and 'Chip-On-Board'(COB) technology allows LED grow lights to achieve more intense light that can penetrate through the canopy much better. The biggest danger with LED grow lights is that old LED technology is still being used today, so if you don't know what you are looking for then you run a serious risk of getting an ineffective grow light that will only really work for cloning/seedlings. At Smokey Eyes we recommend going for Quantum boards as this is the newest and most proven technology, whereas we recommend staying away from the 'purple-coloured' (blurple) LED grow lights as these have shown to be inconsistent and unreliable, especially for flowering plants.

  •  LED Light Costs and Expected Lifespan

LED grow lights vary in price from about R2 000 - R20 000 depending on wattage and quality. When it comes to LED grow lights, you get what you pay for, so don't expect to save money when buying these, but with a 5-10 year lifespan and lower electricity costs, its definitely a great option to consider investing in. 

  • Yield per LED Light

0.5g-1.8g per watt which depends heavily on the quality of the LED grow light


  • Pro's and Con's
    • Pro's:
    1. Cheapest to run of all grow lights (most effective use of power)
    2. Reliable and consistent. 
    3. LED lights are much cooler than HID lights, almost negligible
    4. Less heat means less Cooling requirement and costs
    5. Dual purpose - can be used for veg and flower (depending on the model)
    • Con's:
    1. High initial cost
    2. Cheaper models can produce "air-ey" buds
    3. Potentially lower yields than HID lights



LEC/CDM/CMH Grow Lights

LEC lights, also known as ceramic metal halide (CMH) or ceramic discharge metal halide (CDM) lights are similar to HID lights, but differ in the type of arc tube used inside the light. LEC lights use a ceramic arc tube, rather than the quartz ones in regular MH lights. This produces a more natural color, more lumens per watt and a longer lifespan. LECs include built-in ballasts, so they are simplistic to setup and use immediately. LECs also give off light that is very similar to the color of sunlight which allows growers to easily spot color changes/ nutrient deficiencies.

  •  LEC Light Costs and Expected Lifespan

LEC grow lights last about 2 years, so that's twice as long as HID bulbs last. However a decent light is gonna cost between R3 000- R5 000.

  • Yield per LEC Light

LEC grow lights produce similar results to HID so you can expect up to 1.5g per watt.

  • Pro's and Con's
    • Pro's:
    1. Emits a natural light spectrum (easier to see your cannabis and spot issues)
    2. LEC lights emit UV-B rays that may improve yield or trichome production
    3. Simple setup and operation
    4. Longer life-span than HID lights
    5. Dual purpose - can be used for veg and flower (depending on the bulb)
    • Con's:
    1. High initial cost
    2. UV-B light is harmful to humans (safety equipment is needed to reduce risk to skin and eyes)
    3. Safety equipment needed for large rooms for eyes
    4. Generates heat like HID


So what's the best grow lights for you?

That's going to depend on who you are and what your needs are. for first time growers, try a smaller grow of 1-2 plants under CFLs, for more experienced growers HID/LED/LEC is the way to go for larger yields of beautiful crops, but have many more costs associated with the grow.

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