All the Different Types of Grow Lights You Need to Know

Look, we all love natural sunlight for our leafy buddies, but when you’re living that indoor lifestyle, you gotta get creative.

That’s where grow lights come into play.

In this guide, we’ll break down the different types of grow lights out there, from the OGs like incandescent and fluorescent to the shiny new LEDs and high-intensity beasts.

Buckle up, because, by the end of this, you’ll be a freakin’ grow light guru, or maybe not.

But first, let’s get one thing straight: there’s no one-size-fits-all grow light solution. The best choice for your setup depends on factors like the type of plants you’re growing, your budget, and how much you care about your electricity bill.

Don’t worry, though, we’ll cover all that juicy stuff too.

Let’s get started right away.

Overview of Main Grow Light Types

There are four different types of grow lights:

  1. Incandescent grow lights
  2. Fluorescent grow lights
  3. LED (light emitting diode) grow lights
  4. And HID (high-intensity discharge) grow lights

Remember that these are parents and they have their children too.

For instance, HID comes with HPS (High-Pressure Sodium), MH (Metal Halide), CMH (Ceramic Metal Halide), and so on.

Let’s dive deeper and understand each one of them at length.

1. Incandescent Grow Lights

Incandescent grow lights were one of the earliest types of artificial lighting used for indoor plant cultivation. Edison’s filament lamps, for example, were among the first artificial lights used for growing plants indoors in the late 1800s and early 1900s.

These lights work by passing an electric current through a thin wire filament, heating it until it becomes so hot that it begins to radiate visible light.

While incandescent bulbs do emit some wavelengths of light in the red and blue spectrums that plants utilize for photosynthesis, they are extremely inefficient at this task.

Only around 10% of the energy consumed by an incandescent bulb gets converted into visible light, with the remaining 90% being wasted as heat energy (source).

This excess heat production is a major drawback, as incandescent grow lights run very hot and need to be kept a safe distance away from plants to avoid scorching or burning foliage.

Another significant limitation of incandescent grow lights is their short operational lifespan.

A typical incandescent bulb will burn out and require replacement after just 1,000 hours of use, whereas LED and fluorescent grow lights can last for tens of thousands of hours.

The broad spectrum light produced by incandescent is also not optimized for plant growth, providing too much energy in wavelengths that plants cannot utilize.

Pros

  • Low upfront cost—incandescent bulbs are inexpensive to purchase initially
  • Readily available—can be found at most hardware stores and garden centers
  • Produce some usable red/blue spectrums that plants need
  • Can generate supplemental warmth in grow spaces

Cons

  • Extremely inefficient use of electricity—high operating costs
  • Give off excessive heat that can damage plants if too close
  • Very short bulb lifespan of around 1,000 hours
  • Non-optimized broad spectrum is not ideal for driving plant growth
  • Inferior growth rates, yields, and plant quality vs. better grow lights

Ideal Uses

At best, incandescent bulbs could potentially be used for:

  • Germinating seeds / seedling growth before moving to better lighting
  • Supplementing bare minimum light needs for low-light foliage plants
  • Extending daylight hours at the start/end of a light cycle

SIDENOTE: Even for these limited uses, fluorescent bulbs are generally a better choice over incandescent in terms of efficiency and cost.

In summary, while it is possible to grow plants strictly with incandescent bulbs, they are by far the least efficient and effective option compared to LED, fluorescent, or HID grow lights.

Any potential upfront cost savings is quickly negated by high electricity usage and frequent bulb replacements.

Incandescent grow lights should only be considered for the most basic of indoor gardening needs like keeping low-light houseplants alive.

2. Fluorescent Grow Lights

Fluorescent grow lights have been around for decades as an affordable and energy-efficient alternative to incandescent bulbs for indoor gardening.

They work by using an electric current to excite mercury vapor inside a glass tube, which produces ultraviolet light that then causes a phosphor coating on the tube to glow and emit visible light (source).

The two main types of fluorescent grow lights are:

  • Compact Fluorescent Lights (CFLs): These self-contained fluorescent bulbs fit into standard lighting sockets. CFLs are available in a wide range of wattage (typically 8-55W) and color temperatures (2700K-6500K warm to cool).
  • T5 Fluorescent Tubes: Linear fluorescent tubes that are larger and more powerful (up to 80W) than CFLs. T5 refers to the 5/8 inch (16 mm) diameter of the tube. They require a separate fixture with a ballast to operate.

Pros

  • Fluorescent is 4-6 times more energy efficient than incandescent, producing 50–100 lumens per watt compared to only around 15 lumens per watt for incandescent (source). This helps to reduce energy bills.
  • Fluorescent bulbs release only about 30% of their energy as heat, compared to 90% for incandescent bulbs, allowing you to position them closer to plants.
  • You can choose “cool white” bulbs with more blue spectrum for vegetative growth or “warm white” for the red/orange spectrum needed for flowering.
  • Fluorescent tubes typically last 10,000-20000 hours or more before needing replacement.

Cons

  • Fluorescent doesn’t provide as high light intensity as HID or LED grow lights, so more bulbs/fixtures are needed to cover the same area.
  • While you can choose between “cool” and “warm” whites, fluorescents don’t offer the precise spectral control of LEDs.
  • Even with a long rated life, fluorescent bulb output declines over time, so replacing annually is recommended.

Ideal Uses

Fluorescent grow lights are a good choice for:

  • Starting seedlings and clones
  • Growing low to medium-light houseplants, herbs, and leafy greens
  • Supplementing natural light for indoor gardening
  • Vegetative growth stages before switching to more powerful lights for flowering

However, for high-light fruiting plants like tomatoes or flowering plants, you’ll likely need to upgrade to LEDs or HIDs once the plants become larger.

Fluorescent grow lights (especially T5) remain a solid budget option for indoor seed starting, low to medium-light gardening, and small grow setups where heat control is important.

But be prepared to upgrade lighting for larger plants.

FURTHER READING: T5 vs T8 Grow Lights: Which Is Better for Your Indoor Farm

3. LED (Light Emitting Diode) Grow Lights

LED grow lights are the cutting-edge solution for indoor plant cultivation.

These energy-efficient lighting systems emit specific wavelengths of light optimized for photosynthesis, allowing plants to thrive in controlled environments without natural sunlight.

LEDs work by passing an electrical current through semiconductor materials, which then release photons in the form of visible light.

Unlike traditional grow lights that produce a broad spectrum, LEDs can be precisely tuned to generate targeted light spectra like the blues and reds that drive vegetative growth and flowering.

The main types of LED grow lights include:

  • Quantum boards (flat panels with evenly distributed LEDs)
  • COB/chip-on-board lights (tightly packed LED arrays for intense light output)
  • And linear/bar-style fixtures that can be daisy-chained together.

Pros

  • Unbeatable energy efficiency, converting most power into usable light for plants
  • The long operational lifespan of 50,000+ hours before needing replacement
  • Run much cooler than HIDs, allowing closer positioning to plants
  • Fully customizable light spectrum tailored for specific growth stages
  • Compact size and low profile enable versatile setups like vertical farming

Cons

  • Higher upfront cost compared to fluorescent or HIDs
  • Require proper layout planning to avoid hotspots and ensure even coverage
  • Risk of light burn to plants if improperly configured or positioned too close

Ideal Uses

  • Commercial vertical/greenhouse farming operations
  • Hobbyist indoor gardens, grow tents/rooms
  • Research facilities requiring controlled light conditions
  • Supplementing natural light for indoor houseplants
  • All stages of plant growth from seedlings to flowering

While the upfront investment is higher, LEDs deliver long-term cost savings and unparalleled flexibility to optimize plant growth. Top-tier brands engineered with quality LEDs are well worth the price.

FURTHER READING: Quantum Board vs COB LED Grow Lights: My Honest Breakdown

4. HID (High-intensity Discharge) Grow Lights

HID, or high-intensity discharge, refers to a type of gas-discharge lamp that packs a helluva punch light-wise.

The core concept?

An electric arc rips through a gas mixture inside a sealed bulb or arc tube, pumping out an insanely bright and intense light like it’s nobody’s business.

Now, two main players are dominating the HID grow light scene:

  • Metal Halide (MH): These bad boys emit a crisp, bluish-white light that’s the bee’s knees for keeping your green friends perky during their vegetative growth phase. Lush foliage and sturdy stems are what we’re after here.
  • High-Pressure Sodium (HPS): If MH lights are the protein shake, then HPS is like a thick-as-hell multivitamin for plants when they hit the flowering stage. The orange-red spectrum emitted by these lamps is a surefire way to trigger those beautiful buds you’re after.

Pros

  • Intense light output for vigorous growth/flowering
  • Lower initial costs compared to LEDs
  • Simple to set up and proven effective
  • Good light penetration through the plant canopy
  • Provides supplemental heating for grow space

Cons

  • Generates tons of heat requiring ample ventilation
  • Less energy efficient than LEDs
  • Bulbs degrade and need replacement every 1-2 years
  • Can’t customize light spectrum like LEDs
  • Increased operating costs from electricity usage

Ideal For

  • Flowering plants – MH for veg phase, switch to HPS for bloom
  • Light-loving crops like tomatoes, peppers, fruiting annuals
  • Commercial grows prioritizing yields per sq ft
  • Growers on a tighter budget willing to manage heat/energy costs

HID is a solid choice for any light-craving annuals, veggies, or flowering plants in general.

Keep in mind LEDs may cost more upfront but HID lighting bills and bulb replacements add up over time.

FURTHER READING: Metal Halide vs HPS Grow Light: Key Differences Revealed

The Importance of Light Spectrum, Intensity and Duration

Let’s get straight to the point – light spectrum, intensity, and duration are the holy trinity that can make or break your indoor farming game.

Light Spectrum

This is all about the different wavelengths or colors that your grow lights are spitting out. Each wavelength does its own thing:

  • Blue light keeps plants compact and gets their juices flowing for epic vegetative growth.
  • Red light is where it’s at for igniting that flower party and pumping out fruits.
  • Full spectrum white covers all bases for plants to thrive through every stage.

Nailing the perfect light recipe can supercharge growth and yields.

Light Intensity

This refers to how much light energy is reaching your plants.

More intensity = faster photosynthesis and turbo growth mode – but only up to a point.

Blast your greens with too much light, and you’ll scorch them to a crisp. Not enough light, and they’ll be starving for energy.

You’ve gotta find that sweet spot tailored for your crops.

Light Duration

Also known as photoperiod, this determines how many hours of light exposure your plants get daily. Some dig long summer days to bloom, while others prefer that short day life.

So, there you have it – spectrum, intensity, and duration control every aspect of plant growth, from seedling to harvest.

FURTHER READING: How Long Should a Grow Light Be On (For Best Plant Growth)

Conclusion

Take a second to pat yourself on the back for leveling up your indoor gardening know-how.

We covered the full gamut – from those OG incandescent bulbs (mostly useless nowadays) to the energy-efficient kings of fluorescent and LED, with a side of those powerful HID rockstars.

At the end of the day, there’s no one “best” grow light.

Your ideal lighting setup depends on factors like budget, grow space, target plant species, and growth stages.

For example, LEDs offer unbeatable efficiency and spectral control but at a higher upfront cost.

Fluorescents are a solid budget option for seedlings and low-light situations. And for those chasing maximum yield in limited space, HID still delivers with intense output.

So, do your homework on each light type’s pros and cons.

Still scratching your head?

Fire away with any questions you might have in the comments below.

Dhruvir Zala

Meet your guide
Dhruvir Zala

I’m the guy behind Farmingram, where I nerd out on all things indoor agriculture. Through rigorous research, my goal is to get more people excited about where agriculture is headed.

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