LED vs HPS grow light competition

Wheel around the LED : Cannabis lighting overview

Wheel around the LED

A highlight of how new technologies such as cylindrical grow wheels and LED lighting can lead to a pocket full of THC.

By Diana Campos

While LED lights may not have been successful when they first appeared on the Cannabis cultivation scene — having failed to meet the appropriate intensity requirements needed to sustain plant life — they have certainly grown to be an efficient and effective alternative choice of artificial lighting for gardeners all around the world. Recent improvements to the technology have made it possible for LED grow lights to take some of the trickiest but most rewarding plants to nurture all the way from sprouting to flowering with less of an impact on the environment and on overall running costs than their competition.

So what exactly is an LED and how can it be used to grow plants?

To begin with, LED stands for light emitting diode. These diodes operate by an optical occurrence known as electroluminescence, which is the direct conversion of electric energy into light. On paper, a single LED is structurally simple: two pieces of semiconducting material form a chip which is held together inside of a transparent plastic case by terminal pins. This case is specifically designed to release emitted beams of light through the rounded end at the top of a bulb — otherwise known as the lens — at different angles. Without this lens, the emission would typically be absorbed back up by the semiconductors.

But how exactly does this chip produce light? In order to explain this phenomenon, let’s take a closer look at the materials that make it up: the two bonded semiconductors. One side of the chip is made up of P-type material and the other side is made up of N-type material. The P-type half of the chip contains more positively charged particles due to empty holes within the material, whereas the N-type half has more negatively charged particles. Once bonded, the two materials form a P-N junction in which free electrons (the negatively charged particles) move to fill up the positively charged empty holes. By doing so, the charges cancel out, forming what is known as a depletion zone in the middle of the chip. Without enough voltage, no current is able to flow across this “dead” zone.

This is where electricity comes in. When the P-type end of the chip is connected to the positive side of a circuit and the N-type end is connected to the negative side of the same circuit, the depletion zone disappears as holes are emptied of electrons. These electrons are then free to flow across the diode and it is this movement which produces photons — a unit of light released as energy by atoms.

The intensity and color of this released light depends on the type of material used for the semiconductors. When LEDs first hit the scene, one of the biggest problems growers had with the product (aside from being way too expensive to fit into their budget) was the fact that only very few colors from the visible light spectrum were available. As every good grower knows, the initial reason for grow lights was to replicate as close as possible the same intensity and spectrum as plant’s natural source of energy: sunlight. As lighting technology and the research behind it has improved, some light companies have drifted from this standard and focused on only the wavelengths that the plants actually have use for.

Now, direct sunlight puts out more than 90 lumens per watt, emits a full-spectrum white light, and has a temperature of 5800 K. This so-called “white” light is actually made up of — quite literally — a rainbow of colors: violet, blue, green, yellow, orange, and red. These colors are measured at different wavelengths with the shorter wavelengths (between 400–500 nanometers) showing up as blues and the longer wavelengths (at around 700 nanometers) showing up as reds. Plants are able to absorb wavelengths that are within the 400–700 nanometer range, and use these different wavelengths for photosynthesis — a process in which plant pigments, such as chlorophyll, convert light energy into food for the growing plant. In order to successfully fuel photosynthesis, the artificial light must be able to give off the same wavelengths of light, and thus the same colors as the sun.

By changing the material of a single LED chip, the wavelength can be manipulated to show any visible color in between ultraviolet and infrared. The most commonly used materials are made up of elements such as phosphides and arsenides for their ability to contribute to electrical conductivity. Thus, a single diode emits a single color of light. An LED grow lamp is constructed when multiple chips housed within their tiny plastic cases are placed side by side onto a panel. These panels can vary in size and assortment of diodes as well as lumen output. It is the way these panels are put together that differentiates one grow lamp from another.

The advantages of owning LED grow lights

Keeping the above technical aspects in mind, there is a list of reasons LEDs are a viable option as grow lights. As previously mentioned, they are extremely efficient, especially when compared to the more commonly used halogen, metal halide, high-pressure sodium, and fluorescent lights.

Unlike incandescent lamps, LEDs do not contain filaments that need to be heated nor do they waste energy by doing so. And since LEDs emit less heat (in exchange for more light), they do not burn out anywhere near as quickly, giving them the lengthy lifespans they are known for. This lack of wasted energy consumption also translates into money saved on what would otherwise be a higher electricity bill. Needless to say, such savings also mean a lighter carbon footprint, made even lighter by the fact that LEDs do not contain harmful toxins such as the mercury found in compact fluorescent bulbs. How’s that for going green?

Even so, the continuing argument made against LED grow lights is the hefty price of the initial purchase. A single LED lamp can double, and sometimes even triple, the price tag of a HPS light that covers the same size area. The larger the grow space, the bigger the investment as more lamps are needed for complete coverage. Almost all manufacturers of LED lamps insist this cost is more than made up for over time with the monthly electric savings since not as much juice is used up. But if that isn’t enough to at least peak your interest consider this: an entire man-made grow-op requires more equipment than just grow lights. Exhaust fans, air conditioning units, dehumidifiers, heaters, CO₂ tanks, and in some instances ballasts, light movers, bulb replacements, and reflective hoods are all heavy-duty items that have been added to the professional garden since its move indoors. Although these items individually may not be as costly as the actual grow light, it doesn’t take an accountant to understand how expensive a fully-installed operation can become.

By opting for an LED lighting system, you can opt out of having to purchase those extra fans or that bulky AC unit, especially if growing in an already too-warm climate; since LEDs do not generate anywhere near as much heat as other types of lights, there is no need to buy equipment that is meant to lower the temperature in grow rooms to an optimal state. It also makes it possible to forget about ballasts, which limit excessive current and prevent bulbs from burning out. The money saved from having to purchase unnecessary gear combined with the money shaved off each month’s electricity bill certainly adds up and it is money that can go towards stocking up on nutrients, testing new grow methods, or… really, whatever it is you want to spend your money on.

But the bottom line comes down to results. Farmers want the densest, most potent nugs and they want them grown in an as efficient manner as possible. This means getting the most out of every square foot of available space. Remember those LED panels from earlier? Well, arguably the best thing about them is their customizability. You see, different wavelengths (i.e. colors) of light are needed during different stages of plant growth. The advantage of the LED panels is that the many small multi-colored bulbs can be rearranged in seemingly limitless combinations to give off different spectrums of light. This is not so with other lamps, whose capacity to produce only one color of light can hinder their ability to give a crop the right amount of energy at the right time. For example, a panel with a high percentage of lights in the red end of the spectrum is better for flowering plants, while one with lots of blues provides the stretch of robust growth sought after during the vegetative state. (That being said, there is a limit to how much blue and red wavelengths a plant can uptake. It should not be mistaken that a panel made up of only blue lights would do more to size than a panel with the “correct” amount of blue and vice versa.) “White” LED lights can vary depending on the arrangement of different diodes in a panel, giving off “cooler” or “warmer” forms of white that mimic the “white” given off by sunlight.

Noteworthy products

The future of LED lighting only promises even more advantages as research into the technology advances. As the legalization of Cannabis continues to spread both nationally and globally, the market for cultivation equipment has never been bigger and it too is expected to keep growing. Here are just a few of the LED lighting companies that are currently leading the way in the production of highly effective grow lights and gear.

Black Dog LED

This company is conveniently located in America’s newly created Mecca for recreational ganja: Colorado. With 15 years of botanical experience under his belt, its founder Corey took an interest in the emerging technology and decided to embark on the LED industry. Not a single light prototype is even considered for the market without first being evaluated with a spectrometer and then used to actually grow with. For products that pass the test, Black Dog LED allows skeptics to view successful results by posting libraries of time-lapsed grows and side-by-side (-by-side) comparisons of their own products vs. non-LED products. And while typed-in customer reviews are great, Black Dog takes it one step up by providing links to third party testimonials where satisfied consumers prove claims such as dense undergrowth and healthy, fibrous roots.

A featured favorite from their Universal series is the Platinum XL-U, which is only one — albeit the largest — in a line-up of six varyingly powerful LED units. This series is the highlight of Black Dog LED’s merchandise, but they are not without their gizmos and gadgets. Two major collaborations, one with Method Seven to retail protective LED glasses and one with Gorilla Grow Tents, have allowed them to expand their line of products. This latter partnership is especially beneficial to gardeners or first-time growers who are looking for a ready-made garden; grow tents ranging from two feet by two-and-a-half feet to nine feet by nine feet, can come as grow room kits complete with your choice in a set of lights, tent extensions,  CanFans, light hangers, and in some instances close quarters brackets.

Lush Lighting LED

In a scene where quality and quantity are equally as important, it is essential to get the science down to a T and this is something in which Lush Lighting LED has undoubtedly succeeded. Over the course of three years dedicated to research and development, they have tweaked the light spectrum given off by their lights and tracked the varying responses in the studied Cannabis plants over and over again. In order to fine-tune this spectrum, Lush has incorporated UV LED diodes for their highly energetic photons. It is features like these, coupled with their commitment to providing the public with the necessary technical information that makes Lush Lighting LED stand apart from the rest. With products like the Dominator 2xXL and unique veg-only units such as the Herbalvador 2X and Vegetator 2X, they have certainly caught the attention of hydroponic stores, head shops, garden suppliers, large-scale grow operations, and even schools in eight (and counting) different states across the nation. Trusted by big names like Oaksterdam University and with appearances in multiple High Times-hosted Cannabis Cups, it doesn’t take a hand-held microscope to see why this company has rapidly spurted in popularity. Owner Matt Johnson is so confident in not only his products, but in the LED light industry as a whole that when asked about the technology’s future, he responded with this: “We honestly believe that all lighting will be converted to LED. It’s not a matter of if, but when.” Set your timers growers, because only time will tell!

Hydro Grow LED

Having started as a retailer of grow equipment and aeroponics systems, Hydro Grow LED now provides some of the most highly engineered LED grow lights on the market. Early on, they partnered with the University of Washington to test and provide feedback on their products. The result of the study led to the creation of the company’s two featured series of lights: the Extreme X2 series and the Sol series. Both series include a modular internal build which allows for the lights to continue to function even if one part stops working. This feature is extremely beneficial for buyers who understand that replacement parts for costly LED equipment do not exist as of yet. The split in their line-up of products allows the grower to choose the aspects that are most important for the grow — either deeper penetration from the Extreme series or wider coverage from the Sol series. To Hydro Grow LED, what the growers want is equally as important as what they need; the CEO of the company states that they have built their lights “around the spaces and shapes of what real gardeners are using, rather than producing ‘UFO’ round designs for square gardens.” It is with an intense passion for their technology and a genuine concern for the indoor gardener that Hydro Grow was able to create lights that Dutch Passion Seed Co. recognized as capable of producing the highest yield ever from a single auto flowering plant (at a whopping 356 grams!)

Still another useful feature of their best-selling line is power-selection, which allows the grower to change the light intensity from low (for seedlings and clones) to eye-piercing (for flowering) as plants grow. But perhaps the most distinctive trait of Hydro Grow LED is the fact that they are the first and only company in the LED grow light industry that offers an LED light for cylindrical grow wheels.

Cylindrical Grow Wheels: The newest innovation in grow equipment

The world of automated grow operations is one that has seen many new mechanisms or so-called systems. From ebb and flow to water culture, indoor farmers are relentless in their endeavor to grow bigger and better crops. These are systems that take a lot of the physical work out of gardening by feeding and watering your garden for you. Such systems are the result of the 21st century’s improvement upon tried and true methods of growing.

One of the newest methods for growing that has recently emerged is vertical gardening. This method turns a light long ways and emerges it into the middle of a crop, instead of the traditional means of hanging a lamp over the top of the crop’s canopy. The reason for this is to penetrate the plant with the same amount and intensity of light from top to bottom, rather than having the plant waste precious energy by stretching itself upwards towards a lamp. What this is meant to do is prevent individual plants from forming main colas with progressively smaller buds underneath and instead grow more decently sized colas all around the plant. Vertical gardening is still in the process of being perfected, but it is a method that shows much promise.

Based in British Colombia, Canada, Omega Gardens has taken the idea of vertical gardening and turned it into the Volksgarden — a one-of-a-kind machine that is not only an automated system, but a rotary one as well. It is a cylindrical garden that can hold up to 80 plants in multiple rows as it spins around a central light, all while being fed! The wheel completes one full rotation every 45 minutes for 24 hours of the day, strengthening the plants as they hang at all different angles, including upside down. The many plants are thus urged to stay stunted in size rather than stretch upwards and each given the exact same amount of light exposure. Being only four feet in diameter, it is perfect for gardeners who want to grow a good amount in a limited space.

And for commercial growing in a limited space, Omega Garden has created a “horizontal carousel” called the Farmdominium, which is a mechanism that holds 36 stacked Volksgarden modules. That’s 2,880 plants growing simultaneously! Just think about how much food, herbs, and medicine can be grown in a single warehouse with equipment like this.

As far as assembly of the product, the good folks at Omega Gardens have posted how-to videos that show viewers how to put together a Volksgarden system, step by step. In addition to the framework, the company offers a 1-400 gallon Mag Drive pump and a Borosilicate glass lamp housing cylinder. The product’s lightweight design makes it possible to move the system as deemed necessary without having to disassemble it. Since the actual lamp is not included, the buyer is able to choose between compact fluorescent or LED lamps (see above) to place inside of the attached glass case.

The futuristic apparatus certainly looks cool, but it is its capabilities that make the Volksgarden a product to keep an eye on, or even give it a try for yourself.