Choosing A Grow Light - LEDs vs the Rest of the World

LED grow lights are filling needs for both commercial and hobbyist growers. Because LED fixtures come in many sizes, they are useful on a large scale in big or multiple grow rooms, and at home in a grow tent or other small space. It's just a matter of choosing the LED that best fits your needs. GrowersHouse offers many solutions in LED grow lights because of the clear benefits LED fixtures deliver: adjustable spectrum on many models; long life, with fixtures often carrying a five-year warranty; low maintenance, with no need for annual bulb replacements and less need to run HVAC systems to dissipate heat; and reduced electric costs.

LED Grow Lights

LED grow lights run cool, but they're hot—hot in the sense that every grower, it seems, wants one. Commercial growers may want banks of them or even rooms full.

And why not? LED grow lights:

• Are reliable.


• Adjust brightness and spectrum on most fixtures.


• Emit close to full-spectrum light, with Chip-on-Board (COB) LEDs the closest.


• Use less power than other indoor grow lights.


• Cut other power costs because they produce less heat and don't require auxiliary equipment, such as cooling and ventilation, to work as hard.


• Spectrum degradation is extremely low, with LEDs losing little of their original spectrum and brightness annually.


• Don't require periodic bulb replacement.


• Last years longer than most competing technologies, plasma being the exception, without needing fixture replacement.

In the long run, LEDs save money, especially compared with incandescents, but also compared with most other types of grow lights. Of course, at this point, incandescents are as dead as Edison. LEDs have a higher average purchase price than other types of lights, except plasma fixtures, which cost more.

How much do LED lights cost? The average cost of an LED fixture on GrowersHouse is approx. $775, which is still $190 less than the average plasma fixture.

Are LEDs right for everyone? Depending on circumstances, including budget, some other lights may better serve a grower, especially one who's just starting out and hasn't yet made a long-term commitment to indoor cultivation.

Let's go through the list of grow light types and see what works, and how costs and performance compare when all factors are considered. Keep in mind that this is not a comparison of individual fixtures. There are many variables not just by lighting type, but even from fixture to fixture among the same type of lighting.

Plasma Grow Lights

A relative newcomer, plasma grow lights have many attractive attributes.

Plasma lights are effective in all plant phases. They're not adjustable but are available with bulbs that are weighted toward blue or red, enhancing their versatility. A plasma light emits a full spectrum.

Like LEDs, plasma lights have no moving parts and have no filament to burn out. Both characteristics mean they last for years. Plasma lights have bulbs that contain a mixture of gases that glow when a magnetron or radio frequency power amplifier ionizes an electronic field connected to the bulb.

It really comes down to whether the buyer is willing to make the initial investment.

How much do plasma grow lights cost? The average price of a plasma fixture on GrowersHouse is $965, a price that's likely to fall as plasma product development increases.

Plasma positives:

• As close as electric lights come to generating a full spectrum that mimics sunlight.


• Cheap to run.


• Long-lasting.


• No need for annual bulb replacement.


• Never need supplemental lighting for any plant phase.

Plasma negatives:

• Initial cost is the highest of any type of light sold by GrowersHouse, at $965.


• Fewer fixture choices.


• Throw off considerably more heat than LEDs, requiring air conditioners, dehumidifiers and fans to work harder and probably eliminating LED-related energy savings for auxiliary equipment.

Great choice for:

Established growers who intend to continue growing for the long haul and are prepared to amortize the cost over several years.

Fluorescent Grow Lights

 

Growers have been using fluorescent grow lights successfully for decades. Their blue-white spectrum makes them excellent for nurturing seeds, clones and young plants. They perform well as vegetative lights. Fluorescents may, however, require red augmentation during flowering.

One advantage of fluorescent fixtures with tubes is that they are not very tall or hot, so they work well on grow spaces built with layers. That effectively multiplies the square footage of growspace, one of the highest expenses for commercial growers.

How much do flourescent lights cost? At an average price of $130, complete fluorescent fixtures are by far the least expensive fixtures to purchase on the GH site.

Fluorescent positives:

• Extremely reasonable purchase cost.


• Long fixture life.


• Good coverage.


• A near-daylight blue-white spectrum.


• Low energy use compared with High Intensity Discharge lamps.


• Multiple form factors available—long tubes, including predominant, thin T5s, and compact fluorescents (CFLs), which have a screw-in mogul base and are about the size of a traditional tungsten light bulb, requiring no special fixture.


• Throw off much less heat than HID lamps; bulbs not hot to the touch.


• Available in high output (HO) versions.


• CFLs fit almost any fixture, typically have integrated ballast.

Fluorescent negatives:

• Have tubes, rather than bulbs, that are awkward to handle and can break if mishandled. (Compact fluorescents are shaped more like traditional light bulbs.)


• Lose a high percentage of lumen output yearly.


• Require annual bulb replacement; HO tubes average about $10.


• May need red augmentation for flowering; removing a regular tube and replacing it with a red tube, however, is relatively easy. Red tubes as little as $6.35 each.

Great choice for:

• Growers using multiple layers in a grow tent or grow room.


• Growers using one light in one tent.

The following grow light types are all considered High Intensity Discharge. In general, fixtures made for one will work with the others as long as ballasts are correctly matched. The average HID fixture cost, including bulbs, on GrowersHoise is about $414.

 

HID Lights

Metal halide grow lights (MH), ceramic metal halide grow lights (CMH), and high pressure sodium (HPS) lights are all considred to be high intensity discharge. In general, fixtures made for one will work with the others as long as ballasts are correctly matched. The average HID fixture cost, including bulbs, on GrowersHoise is about $414.

MH (Metal Halide) Grow Lights

 

Long the standard for indoor grow lights, MH bulbs come in single- and double-ended versions. Each type requires its own fixture, but brands typically are interchangeable from fixture to fixture. MH bulbs emit light when electric current excites the gas inside the bulb. The gas is there in place of a filament, so MH bulbs last longer than incandescents did.

The spectrum is very close to daylight, making the MH grow light useful in all growth phases. Its ability to emit light in the blue range makes it favorable for propagation. It also has good UV light output. Flowering, however, may require red supplementation when using MH lights.

MH positives:

• Low purchase price, with the average price on GrowersHouse for an MH fixture with bulb(s) being $414.


• Produces good amount of blue light, which aids propagation.


• Produces lots of green light for strong vegetation.


• Penetrates canopy well due to a spike in the yellow part of the spectrum.


• Discourages stretching by plants.


• Many wattages available, including 400w, 600w and 1,000w.


• High lumen output per watt.


• Variety of ballasts available.

MH negatives:

• More expensive to run than LEDs.


• 20,000-hour life but quick degradation of original light spectrum, requiring annual replacement; the average MH bulb price on GrowersHouse is $82.83.


• May require supplemental CMH lighting during flowering for more red.


• Not as full a spectrum as LEDs.


• Higher electrical consumption than LEDs.


• High heat given off, making ventilation equipment work harder.


• Bulbs get so hot they can cause burns if touched.

Great choice for:

• All-around lighting.


• Lighting where ceilings are high to help dissipate heat.


• Because of low purchase cost, new commercial growers not yet committed to long term.

CMH (Ceramic Metal Halide)

Shown above: Nanolux 100W - 3K CMH light.

CMH grow lights, a relative newcomer, are effective and reasonably economical. The spectrum is a mix of what's produced by an MH bulb with what's produced by an HPS bulb, but without the red bias. The average CMH fixture purchase price, although higher than for fluorescents, HPS or MH fixtures, is lower than LED and Plasma lights.

How much do CMH grow lights cost? The average CMH fixture on GrowersHouse costs $425. Like all HID lights, CMH bulbs require a ballast; depending on the fixture, that may add about $100. Some MH fixtures, with the right ballast, can use MH, CMH or HPS bulbs.

The CMH spectrum is an all-around light usable for all cycles of plant life. For flowering, however, supplementing CMH or replacing the bulbs with MH or, even better, HPS lamps is recommended. That becomes simpler if the fixture/ballast combination can handle either CMH or the other bulbs. NOTE: Digital ballasts must be mated to a digital bulb of equal wattage. Digital ballasts will also run either MH or HPS as long as the wattages match.

CMH bulbs are hardier than MH and HPS, retaining about the same amount of the original spectrum at 20,000 hours as the others maintain after just 10,000 hours. Still, CMH bulbs should be replaced yearly. Because of annual bulb costs and supplemental bulb costs, replacement costs are considerably higher than for LEDs. (See our detailed LED vs. CMH Grow Light Cost Comparison.

CMH positives:

• Higher reliability than MH and HPS.


• Lower upfront costs than for LEDs. The average CMH fixture on GH, including bulb and ballast, costs $425.


• Lower electrical costs than for MH and HPS lamps, partly because a lower wattage can be used with CMH to achieve lumens and PAR equal to higher wattages in MH and HPS.


• Lower mounting possible because of lower wattages.


• Good penetration of canopy because of green and yellow light in spectrum.

CMH negatives:

• Relatively high initial purchase price compared with MH and HPS.


• Yearly bulb replacements required.


• Supplemental red lighting recommended for flowering.

Great choice for:

• Home gardeners using one light in a grow tent.


• Growers going commercial who have not yet made a long-term commitment.


• Commercial growers seeking lower electrical bills who can make the switch economically by using existing MH fixtures and existing ballasts, or by using existing fixtures and adding compatible ballasts.

HPS (High Pressure Sodium)

Above: The Digilux Double Ended 1000W.

These HID lights, which emit a visible orange glow when lit, do indeed have elevated levels of orange and red in their spectrum. They are especially valuable during flowering because of their heavy orange and red output. They require a ballast and, with the proper one, can use many MH and CMH fixtures.

How much do HPS grow lights cost? Figure on an average cost of $414 per fixture.

HPS lights do not have much blue and green in their spectrum, making them less than optimum for vegetative growth.

HPS bulbs consume a lot of electricity—about the same as an MH light—and turn much of that energy into excess heat, using electricity to power fans and air conditioners for cooling. That means they will not save money on operating accessories as LED lights do, but they are more economical to run than MH bulbs.

HPS positives:

• Broad spectrum with plenty of red for excellent flowering.


• Affordable purchase price, with the average HPS fixture about $500.


• High lumen output and better PAR efficiency than fluorescent lights; 600w lamps are especially efficient at producing light for photosynthesis.

HPS negatives:

• Produce a lot of heat, increasing cooling costs.


• Use about the more electricity as an MH lamp, and much more electricity than LEDs, resulting in higher operating costs.


• Can burn plants if mounted too close to the canopy, especially if 600w or 1000w.


• Require yearly bulb replacement due to loss of lumen output and spectrum variation over time; the average HPS bulb price on GH is $68.53.


• May require supplemental MH light for more blue during propagation and vegetation.

Great choice for:

Supplementing fluorescent, MH or CMH during flowering

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