Nothing is more important than light.
When gardening indoors, the type of light can make all the difference in plant health and productivity.
There are a lot of lighting options to choose from, but most gardeners start with fluorescent grow lights, like the Agrobrite series from Hydrofarm.
They begin with fluorescents for a reason: they have a number of advantages over other types of plant lights.
Once you expand the size of your garden, the advantages will begin to lose out to the disadvantages, but in the beginning, fluorescent lights often make the most sense.
If you’re not sure which type of fluorescent bulbs are best for your needs, check out this article.
Benefits of Fluorescent Lighting For Growing
- Very low heat emission, making them safe to place close to plants
- High energy efficiency
- Lower initial costs compared to other types of lighting systems
- Can be placed in different positions to ensure all parts of the plant have adequate lighting
- It is the best type of light for seedlings and clones, due to low radiated heat
- Can accelerate plant growth when used as under-lighting for outdoor plants or in greenhouses
- Fluorescent lights produce the right intensity of light for healthy stems and foliage
- They can produce sufficient energy for flowering (though this is not their strength)
- To reduce energy consumption, the fluorescent light can be used to supplement other types of grow lights
- Fluorescent lights are very simple to use
- They have a natural light spectrum lying between the red and blue wavelengths, which ensures healthy plant growth and productivity
- They are the best for most house plants due to the full daylight spectrum, similar to the sun
- Produced in a wide range of sizes and shapes, which means they can be placed in varying positions, including in close proximity to plants, which adds to the convenience of use
- Come in a range of light colors (warm white, cool white, daylight, etc.)
- Can be hung vertically and horizontally
- Most have a life span of tens of thousands of hours of service
- They have no-glare light which is friendly on the eyes
- Some of the latest T5, T8 or CFL bulbs can give more than 90% of the solar spectrum
- Fluorescent light tubes fit easily into reflectors, so you can get set up very quickly and easily
To make clear why these fluorescent lights are often the best grow light option, it is necessary to understand the disadvantages of each of the other types of grow lights.
Here are the other man types of plant lights, with their disadvantages as compared to fluorescents highlighted.
HID Grow Lights In General
- These lights have sealed metal caps which allow gas to escape; this means the output and spectrum degrade over time and begin degrading almost instantly
- Unlike fluorescent lights, these need to be frequently replaced which adds to the costs
- HID lights consume a lot of energy, which increases operating costs over fluorescent lights considerably
- Unlike the fluorescent lights, they emit a lot of heat, which can harm your plants if hung too close
- They produce an uneven light spectrum
- There is an additional cost for cooling equipment to deal with the heat; this is not necessary with fluorescent lights
- They require other equipment, like air conditioning systems, compatible ballasts and reflector hoods; with fluorescents, these are all included in the fixture
Metal Halide Bulbs (MH)
- The bulbs pose a health risk due to mercury content
- Operating costs are higher than for fluorescent lights due to the need for compatible ballast and reflector hoods
- Increased costs because they need to be replaced after a few months to a year of use
High-Pressure Sodium Bulbs (HPS)
- These also require a compatible ballast and reflector, which adds to costs
- Their high heat output necessitates ventilation and air conditioning which is something you won’t need with fluorescent lights, unless you install a ton of them
- High pressure sodium lamps must be replaced every few months to a year, as opposed to fluorescent lights which have a longer life span
Ceramic Metal Halide Bulbs (CMH)
- even higher costs than MH or HPS and require similar equipment (but not the same), so you have to buy a whole CMH system
- heat output is much lower than other HID lights, making this an advantage over fluorescent light
- longer bulb lifespan that fluorescent light
- perfect color spectrum for all stages of growth
- much more powerful and efficient than fluorescent bulbs
LED Grow Lights
- The purchasing cost of LED lamps is significantly higher than T5 fixtures or CFL bulbs, especially for high quality brands. That said there are a few good cheap LEDs on the market these days.
- To achieve the desired growth and yield from your plants, you may need to use more lights and place them close together, if you go with less expensive LEDs.
- You may find it difficult to get replacement diodes for many models.
- If you go with older models or less expensive ones, you may not see great results due to their limited and uneven spectrum.
Induction Grow Lights
- High initial costs compared to fluorescent lights
- Poor growth of plants with resultant lower flower density
- May require additional costs to purchase a flower initiator, or another means of increasing flower productivity
Plasma Grow Lighting
- The purchasing cost for plasma lights is quite high compared to CFL or T5 lights
- Prone to magnetron failures
- Difficult to replace
- They lack deep red spectrum light, so you may have to purchase supplemental lighting, which will add to your costs
Advantages Of Fluorescent Grow Lights: Final Thoughts
As you can see, there are many benefits of fluorescent lighting for growing plants. It is inexpensive and works very well for small gardens and plants with low light requirements. Our article comparing fluorescent vs LED grow lights directly has more on this.
For plants with high light requirements, like cannabis or tomatoes, T5 and CFL bulbs can work well, too, but only for a small grow.
For larger grows, you’ll want to use a more powerful type of plant lights, like LED or HID. When it comes to T8 vs T5 grow lights, T5 is the newer technology, more efficient, and preferable in most situations.
- AFC Greenhouses: http://www.littlegreenhouse.com/guide3.shtml
- Urban Organic Gardener: http://www.urbanorganicgardener.com/2012/02/how-to-select-the-best-grow-light/