Compact Fluorescent Lighting (”CFL”) Grow Lights-
A CFL GROW GUIDE
Compact fluorescent light (“CFL”) are easily recognized by there spiral, curly design, which results in them being more compact than regular fluorescent tubes. The CFL bulb is a vast improvement over the Thomas Edison (1880 patent) incandescent light bulb.
The CFL bulb though is not as popular as it used to be as other newer, and more versatile grow light technology, has become more popular. For example, when it comes to LED vs. CFL grow lights; LED technology is superior. However, growing cannabis with CFLs does have a purpose and it can be the right choice for many individuals.
You, you may already be familiar with the CFL grow lights, and just want to get to the reviews. So, I will review CFL grow bulbs first. However, if you want to read helpful, background information, for compact fluorescent grow lighting, you can go down to the appendix or simply select what interests you in the table of contents.
CFL Grow Lights Longevity
Manufacturers claim that a typical compact fluorescent light bulb can last for up to ten years. However, the ten years or so claimed lifespan for CFL light bulbs is an estimate based upon the bulbs being used in houses for around three hours a day. So, you should not expect your CFL bulbs to last for ten years or so.
Best CFL Grow Light Bulb Review
Philips T2 Spiral CFL Light
- Listed Wattage: Varies (See Listing)
- Lumens: 1,600
- Color Options:2700K, 5000K
- Size: 4.13” x 2.28” x 2.28”/3.8” x 2” x 2”
- Weight: 14.4 Oz-(2700K), 16 Oz-(5000K)
- How Many? 4 to 6 Pack
- Energy Star Certified? Yes
- Warranty: Limited 9 to 11-Year Warranty (Based Upon 3-Hours A Day Use)
- What Plant Growth Stage: Flowering/ Vegetative
- They are heavily Vetted- Over 1,700 reviews.
- Ratings- Phillip’s CFLs have an excellent overall rating for energy efficiency, brightness, longevity, value, and more.
- Grow Light Use-18 comprehensive reviews that specifically mention the Phillips being purchased for as a grow light.
- Longevity-A few complaints mentioning of a few bulbs died prematurely.
- Packaging Issues- A few customers complained about receiving a broken bulb in the mail.
Phillips grow light bulbs are very popular on Amazon. Also, only a few reviews mentioned bulbs burning out prematurely and that the bulbs were broken when received in the mail. I feel these complaints though, are flukes and are not overall indicators of the quality of Philips CFls.
The reason for my above assertion is that Phillips CFLs have a very high overall rating for longevity, and also they have a high rating for packaging. Because of these high ratings, I am confident that an issue of the CFLs dying out too soon or sub-standard packaging is not a trend, and you should feel confident buying Phillips CFLs.
In conclusion, based upon the overwhelmingly positive and thousands of reviews, you cannot go wrong buying Phillips CFL bulbs.
CFL 2700K-Pack of 3
- Listed Wattage: 20Watts
- Lumens: 1,300
- Size: Overall length is 4″
- Color Options: 2700K
- Weight: 8.8 oz
- How Many? 3 Pack
- Energy Star Certified: Yes
- Lifespan:10,000 hours
- What Plant Stage: Flowering
- Compact-Praised for being micro-size.
- Good Reviews-Overall positive reviews with over 70% perfect reviews.
- Flowering Stage-2700K for flowering works well
- Sparse Number of Reviews: Their are only 100+ reviews. (I.E., Phillips CFL has over 1,700 reviews) Therefore, it is hard to evaluate any positive quality trends for the Sylvania, CFLs. Additionally, due to the lack of reviews, Amazon does not have overall ratings for specific issues like longevity, brightness, etc. Phillips had.
- Packaging: Majority of negative reviews noted that the Sylvania CFL bulb was poorly packaged, which resulted in broken bulbs being received. Even five-star reviews stated that they received a broken light or two.
- Burned Out: Few reviews mentioned that the bulbs died out prematurely.
At least online, I do not recommend that you purchase these reviewed Sylvania CFls. The reason for this is two-fold; lack of reviews and a high number of reviews where customers complained that they received a defective product.
Satco S8201 9 Watt (40 Watt) Mini Spiral CFL
- Lumens: 500
- Color Options: 2700K
- Size: 2.01″ x 2.01″ x 4.02″
- Weight: 2.11 oz
- How Many?
- Energy Star Certified? Yes
- Lifespan: Not Listed
- Warranty: 3 years limited
- Numerous Reviews: 500+, overall positive reviews
- Compact: Very compact, at 3.38″, the Satco is among the smallest CFLs available.
- Customer Service: Buyers noted that Amazon, with no hassles, replaced a broken and prematurely burned-out light bulb.
- Unknown For Growing: No mentions either positive or negative, saying that that Satco was used for a grow light.
- Negative Reviews: There were around 10% negative, one-star reviews.
- Starting Time: A few reviewers mentioned that it takes a while to start up and get to full brightness.
Final Thoughts And Recommendations
CFL grow lights are a good choice for the hobbyist or newbie grower, or for those that only want to grow one or two plants. However, if you are going to be growing more than two marijuana plants; it is highly recommended that you look into using a LED grow light.
Click Here to find out my take on LED lighting technology.
As for the “Best CFL Light Bulbs”, I highly recommend Phillip CFLs. The main reason for my recommendation is that Phillips has over 1,700 overall positive reviews. Additionally, Phillips CFLs, have a high overall rating for issues concerning brightness, packaging, etc. So, based on the number of reviews, and the highly positive reviews, the Phillips CFl bulb is recommended.
US Government Info For CFLs
For more general, US Government issue, info on the CFL light bulb Go HERE
PROS And CONS For CFL Cannabis Grow Lights
These PROS and CONS mainly pertain to CFL in comparison to incandescent bulbs.
- Cost: They may initially cost more than incandescent bulbs. However, they can last up to ten times longer than the 1,000 hours average lifespan of the incandescent bulbs. (Last up to 10,000 hours) Also, startup supplies are significantly less than LED lights.
- Energy Savings: On average, with CFLs, you will use 75% less energy than with traditional, incandescent lighting, which can add to impressive electricity bills savings.
- Produces Less Heat: CFLs have less heat output, which means that they can be placed closer to your plants, which makes them work well in tight places. Also, depending upon the size of your grow area and the overall grow room environment, you may not even need a cooling system.
- Budget Option: CFLs do not run hot. Therefore, depending upon the size of your grow area and the overall grow room environment, you may not even need a cooling system.
- Easy To Set Up: You don’t need any special equipment to use CFLs as, for many bulbs, all you have to do is simply plug the light into a traditional light socket. This is different than growing with T5 fluorescent grow lights that require a separate ballast. (Ballasts regulate voltage in regular fluorescent lighting and also HID lights) For CFLs, the ballast is included in the bulb.
- Beginner Friendly: Great way to learn how to grow weed as CFLs work well for growing just one to two marijuana plants.
- Compact: They produce less heat than incandescent bulbs, which means they can be placed closer to your cannabis plant. Consequently, because they can be placed closer, CFL grow lights work well for tight grow areas. CFL bulbs can make an excellent CFL closet grow light setup.
- CFL Yield: By Growing cannabis hydroponically, you can realistically expect from one to three ounces of marijuana with CFL grow lights. (The exact yield depends upon the strain, size of the marijuana plant, etc.)
- Versatile-A CFL bulb can still be used for the vegging plant life cycle if you decide to switch over to LED grow lights.
- Environmentally Friendly: CFLs use around 75% less energy than incandescent light fixtures. This 75% energy savings, over time, can save you quite a bit on your electricity bills. Also, energy savings help reduce greenhouse gasses.
Studies have shown that the US consumer changing just one incandescent light bulb to a CFL bulb could save enough energy to power three million homes.
- Labor Intensive: A CFL grow setup is simple and an excellent choice for one to two cannabis plants. For example, when growing Cannabis with CFL, you do not need a ballast. Also, as CFLs don’t run hot, external cooling may not even be required. CFLs, though, should be placed approximately eight inches to a foot from your cannabis plants, which means as your plants grow, you will have to move your CFL lights. You may have to adjust the height of the lamp for your cannabis plants from one to two times a week, which can get tedious if you have more than two plants. And if you forget to make the height adjustments, your cannabis plants may burn, or the yield will be reduced.
- Hazardous Material: CFLs contain the toxic substance mercury. So, you need to be extra careful that you don’t break any bulbs. If you do break any, you will have to make sure that you clean up your area and properly dispose of any broken bulbs.
- Dimmer Switches: If you desire dimming, you will have to buy special, and more expensive, dimmable CFLs.
Kelvin, Watts, and Lumens, Measurements
You will see Kelvin, Watts, and Lumen’s measurements when you are shopping and comparing light bulbs, which can get quite confusing. I’ve included a brief explanation below.
- Kelvin-Tells you what light color spectrum that your bulbs will emit and is a guide for you to selecting a grow light that best mimics the particular time outside during the year. It is scientifically known as a color temperature measurement. Kelvin represented by K and different ranges represents different colors.
- Watts-Wattage is a measurement of the amount of light intensity that a grow light gives off. A rule of thumb is more watts equals a better your cannabis yield will be.
- Lumen– The lumen output is a measurement of the brightness level of a lighting fixture. The higher the lumens number the brighter the light bulb. Also, lumens are used to help you figure out how many lights you will need in your grow space.
Is LED Better Than CFL For Growing?
LED Vs. CFL Grow Lights
The simple answer to this question is yes. Granted, the CFL grow yield is not as productive as LED grow lights. A CFL grow setup though, under the right situation, can be an acceptable and even better choice for some cannabis growers. For example, growing with CFL is perfectly fine under the following situations:
- Beginner CFL Grow light Setup: Because of minimal equipment needed, CFL works well for newbie cannabis growers who want to keep their costs to a minimum.
- Small Operation: CFL grow lights work well if you are only wanting to grow one or two marijuana plants.
- Small Growing Space: The CFL light is a compact alternative to bulky, traditional fluorescent tubes, which means that they are able to fit in tight places.
Full Spectrum CFL Lighting
On Amazon, you will see a few compact fluorescent light bulbs that claim to be full spectrum. Here, is one example:
However, when looking at the lumens rating you will find out they are not actually a full spectrum light bulb. So if you want to maximize your yield you would need to use different bulbs for the various grow cycles; so, you can get the multiple color spectrums that are needed.
The Health Concerns of Mercury Contamination With Compact Fluorescent Lighting
CFLs contain a small amount of mercury. (From one to four milligrams per bulb) Mercury is a hazardous substance that, when ingested can cause neurological damage, concentration problems, memory problems, motor skill deficits, lower IQ, fatigue, and paralysis.
The phrase “Mad as a Hatter” originated from the 18th and and 19th century hat makers (“Hatters”), who used mercury nitrate to help turn small game (rabbits, mink, etc.) into hats. As you would imagine work safety standards were lax back then; so, these hatters were subject to dangerous long-term mercury exposure. This prolonged exposure resulted in many “Hatters” having mental and physical problems, like mental and emotional instability, speech impediments, tremors and even hallucinations.
Mercury is not released, when a CFL grow light is on. However, mercury contamination can occur if a CFL bulb is broken or disposed of incorrectly. Also, exposure from a CFL grow lights breaking could cause mercury poisoning for the consumer if the broken CFL bulb contaminates the product, and the consumer ends up using the mercury-laced cannabis.
Miscellaneous, Health Issues
The following, which hasn’t been proven, are potential health concerns caused by CFL light exposure:
- ADHD symptoms
Miscellaneous Problems That Will Likely Not Matter Much To Growers
Below, are a few problems that should not be a big issue for a cannabis grower.
- Running At Full Speed: At around 30 seconds to three minutes, CFLs can take a long time to fully warm up. However, as you will turn your lights on and off minimally, this should not be a major issue.
- Health Concerns: For most indoor gardeners, light exposure hazards from CFLs, especially if you use a grow tent, are minimal. These following complaints though would mainly pertain to people who use CFL lighting for household purposes that result in hours of exposure: Migraines, Anxiety, Tiredness, Seizures, and ADHD like symptoms.
Best Practices For CFL Bulbs
- Dimmable Bulbs: Only use dimmable CFL bulbs with a dimmer switch.
- Three Way CFL Bulb: Only use three-way bulbs on three-way sockets.
- Screw Them In Right: Screw the bulb by holding the white plastic part of the bulb and not the glass tube.
- Socket: Not all CFL bulbs can fit into an ordinary socket. So, make sure that the bulb you are buying will fit any sockets that you currently are using.
Correct Method For Screwing In CFLs
What CFL Light Is Best For Growing?
When growing with CFL, to maximize your harvest, you will need to have different colored bulbs that cover the various light, color spectrum. This means that you will need a different color, bulb for the vegetative and flowering growth stage)
The different bulb colors for CFLs mimic the sun during the season when the vegging and flowering phase occurs. To make sure that you get the correct color, you need to reference the kelvin measurement. So, to answer this question, the best CFL light (or bulb) depends upon whether or not you are in the flowering stage of the vegetative stage of plant growth.
The following are the recommended CFLs color bulbs for the vegetative and flowering stage and the Kelvin measurements.
Seedling Growth Stage (5000k to 6500k)
The vegetative growth stage, in nature, is where the growth starts rapidly. So, it is very important that your plants get enough light. CFLs at 5000k to 6500k are the recommended bulb for the vegetative stage in cannabis. These bulbs have a blue tint and are often called daylight bulbs. The best CFL For flowering Stage is 2700K to 3000k.
Flowering Growth Stage
The flowering stage is the final growth stage in plants, and in nature, this stage occurs during the late summer days, when the day becomes shorter and the sunlight isn’t as bright. To copy this plant growth stage you need to use CFLs that mimic the sun during those months. CFLs with a Kelvin (“brightness”) range from 2,700k to 3000k work best, and 2700k for flowering is ideal. These bulbs are also called “soft white” or “warm white light.”
Light Bulbs Between (3001k to 6549K)
This range is called the cool white or bright white range and these bulbs should not be used for indoor growing.
How Many CFL Light Bulbs Should I Buy For My Indoor Growing Operation?
Why Should You NOT Use The “How Many CFLs Per Plant” or How many CFL watts per plant” method.
You can estimate the number of CFLs that will be needed by either measuring the square foot (preferred method) of the growing area or the number of cannabis plants that you will be growing. However, the square foot method is more precise and should be used. To use the square foot method you first need to plan ahead by asking yourself these fundamental questions:
- How big is your grow area or grow tent?
- How many cannabis plants do you want to grow?
- How much do you want to spend?
- What type of cannabis strain are you going to grow?
Because of the above variables the square feet method is the more accurate measurement. As a result, I will just include the square foot mentioned and not the inaccurate lights per plant method of calculation.
Lumen and Watts
The wattage number is the most common method to help you determine the indoor lighting that you will be needing for cannabis. However, the lumen rating is also a good way to also help you determine the number of bulbs that you will be needing. Therefore, I will include both the lumen and watts, standards, to help you purchase the correct number of lights for your indoor gardening. First, though you need to understand the following background information.
More Lumen, More Watts, Within Reason, Means Better Results
A general rule of thumb is that, within reason, the higher lumen and watts, the brighter it will be, which in turn means you will have a better yield. However, common sense needs to apply; so, you wouldn’t for example, have ten 1,000 watt bulbs for one plant. Instead, based upon industry guidelines (I will explain it later) you should aim to get a grow light that has either most watts or lumens that you can afford and will work in your grow area.
How Many CFLs Needed Per Square Foot?
For a quick review, Lumen is a measurement of the overall brightness of a lighting source. The higher the lumen number, the brighter the light. And the brighter the light (lumen) the better results you will likely see. Generally, depending upon the size of your cannabis plant or plants, the strain, your budget, etc., the higher the lumen number the better. The following is based upon one, average-sized, cannabis plant where the light is placed from 3″ to 5″ away from the plant.
- Square Feet:2,000 to 7,500 lumen
The number of watts is the traditional method for deciding the number of bulbs needed per square feet.
- Square Foot: Flowering Stage (60 minimum to 100, 100-watts is what you should shoot for)
- Vegging Stage, Seedlings and Clones: 60 Watts Per Square Foot
*Actual Not Equivalent Wattage-Compact fluorescent light package’s list both actual and equivalent wattage, which can be a bit confusing when you are wanting to apply the above rules. Actual is the amount of energy that the light uses and equivalent is what the light would use if it were an incandescent light. Admittedly, this can get a bit confusing when you are trying to buy the correct number of bulbs for your grow setup. However, all you need to remember is to use the actual wattage and not the equivalent wattage that is listed.