In some situations, regular HID lights, or LEDs, are either too expensive, or burn too hot for a small space. Growing cannabis with CFLs, is a great way to provide your plants with enough light to grow, but keep heat and energy consumption low.
CFL stands for compact fluorescent lighting, and though they are not high intensity lights, they can still produce quality cannabis. Though, you will getter a better yield with LED or HID lighting, sometimes CFL is your only option.
The grow may take a little longer. But you can grow good cannabis under CFL’s. You just have to use them correctly.
If you are growing cannabis with CFL, or think it is your best option, then feel free to ask for help in our cannabis growers forum
Reasons to Grow Cannabis using CFL’s
CFL’s will run cooler than most forms of grow lighting. Because of this, you can place them as close as 2-3cm from the top of the plants. Also, because they do not burn so hot, they require far less extraction to keep the room cool. You will still need extraction to remove stale air from the grow room. But you have the option of using smaller extraction, or a dimmer switch to slow the fans speed down.
Growing cannabis with CFL’s will also use less electricity. It is not a huge difference, as you have to use many bulbs to meet the lumen needs. But any cut in energy consumption is good. Plus, with HID lights, a lot less energy is wasted as heat.
CFL’s are best used for grow rooms under 1m squared. They can also be used by growers on a budget as these lights are reasonably cheap to buy, or you may already have some around your house that you could use.
Your CFL grow can be up and running for under the price of a few grams of cannabis from the black market.
Growers can use a few 20w CFL’s and a couple of PC fans to grow cannabis in a small box or cupboard! This is called stealth growing.
If you would like to grow cannabis, but have no space for it, you could grow using CFLs, in an old PC tower, with a few PC fans. See our guide on stealth growing for more information.
Using CFL’s as Supplemental Lighting
CFL’s can also be used as source of supplemental lighting. By adding a few into the canopy of a HID/ LED grow, they can provide the plants with additional lighting, where the bigger lights can’t reach.
Also, because of the low heat output, these lights can be hung in between flowering plants.
This will increase yield and improve the overall quality of your cannabis.
How to Grow Using CFL’s
You can grow good quality cannabis using CFL’s, you just need to know how, and follow some simple rules to offer the best light you can to your plants.
Keep Bulbs Close
Keep the bulbs as close to the foliage as possible. 20w CFL’s can be as close as 1-2cm, but 250W CFL’s need to be between 2-5 inches from the canopy. Due to the inverse square law, your plants get alot more lumens from the bulb when it is closer to them. This is another reason why CFL’s can be used to grow cannabis. Because you can get them so close to the plants, you are delivering a lot more light than you think.
Plants Should be Topped and Trained
When growing cannabis indoors, you should always top your plants at least once. This is especially important when growing cannabis with CFL’s. You need to keep the canopy level, to offer the best spread of light to the plant.
Top your plant, and low stress train the side shoots with garden wire. Doing this will “spread” the plant out horizontally, and allow more of the plant to receive a good amount of light. This will ensure a level canopy, and the whole plant will be an equal distance from the light. This would not be the case if you didn’t top and train.
Having tall plants is no good when growing cannabis with CFLs, as you can only provide light to the tallest part of the plant. Low Stress Training will allow the plant to be spread out further, giving it more light. If you’re going to grow cannabis using CFL’s, you must top and train!
Defoliating Your Plants
Light penetration when growing cannabis with CFL’s is weak, compared to HID and LED lighting. This means, the light can not penetrate too deeply into the canopy. So any leaves just a couple of inches below the canopy, will not get enough light.
To let more light penetrate through the canopy, selective thinning or pruning must be done. This will increase yields and keep your plant happy.
Sea of Green under CFL’s
Growing a sea of green with CFL’s can bring excellent results with both yield and time. But to do this, you must have access to cuttings from a mature “mother” plant. Once rooted, the clones can be put straight into flower. Use small deep pots, around 2-3L volume.
Each clone should yield around 10g dry cannabis. If you plant 2 new cuttings every 2 weeks and flower straight away, will pull in on average 20g per 2 weeks. With practise this can increase.
Final Thoughts on Growing Cannabis with CFL’s
CFL’s are a viable alternative in many situations. From growing in small spaces, growers on a budget, supplemental lighting, and stealth grows.
These can be used to grow cannabis, but HID and LED lighting should be used where possible. CFL’s are good to use, when you have no other choice. For bigger yields and faster growing plants, HID is the best option. But if you put one of those in a small space, your plants will soon be cooked.
Like everything in this hobby, it depends on what is good for you. If CFLs seem like a good option for you, then go for it. When you’re smoking your own home grown, I guarantee you will not be disappointed with the results.
Sign up to our cannabis growers forum
Thanks for reading! You can find more information on anything related to growing in our cannabis grow guides. All of our guides are written by experienced growers, and members of our cannabis growers forum. If you have any questions, sign up. It is free, and we are always happy to help!