Smaller LED Fixtures Can Be More Efficient

With HID lights, the most efficient fixtures are the largest and most powerful. This means that it is better to have one large fixture rather than multiple smaller units. However, the most efficient HID lights are simply too large for many home growers.

With LED lights, some of the most efficient units are small fixtures. Indeed, the HLG 65 that we recommend covers only about 2 sq. feet and the Mars TS 1000 covers just about 4 sq. feet. We suggest getting several of these lights and running them in an array.

Using smaller fixtures in an array offers several advantages over using one large light. Small fixtures allow you to distribute the light better throughout the grow space. They also allow you to hang the lights closer to the plants, which saves precious vertical space inside a grow tent. With a large light, you need a higher hanging height because the light source is more intense, and the light needs to distribute. Another advantage of using several smaller lights is that it allows you to adjust the height of individual fixtures to optimize the hanging height above different plants. Finally, having small lights allows you to start each grow using just one light, which saves electricity. As the plants grow, you can simply turn on the additional lights.

Ignore the Marketing Hype

The amount of deception in the LED grow light market is truly remarkable and disturbing. There are no standards for the claims that many manufacturers make about how their lights compare to traditional HID lighting. As a result, many manufacturers grossly inflate the perceived efficiency, power, and value of their lights. For example, the Viparspectra V300 light that we show in the table above is advertised as being equivalent to a 250w HPS. However, using PPF, we estimate that it is only equivalent to about 106 watts of HPS lighting. We recommend that you ignore the equivalencies that manufacturers publish. Instead, use PPF data and our Grow Light Calculator to evaluate the total power, efficiency and relative costs of different lights.

Avoid Blurple Lights

When LED grow lights first hit the market, they were less efficient than standard HID lighting. In an effort to improve efficiency, LED manufacturers focused on red and blue spectrum light. This led to the "blurple" grow lights, which continue to dominate the low end of the LED market. "Blurple" light is more efficient to produce, but it offers an inferior spectrum for growing cannabis. We recommend that you choose only "full-spectrum" LED grow lights.

Focus on PPF not the Brand of LED Chips

Many growers get caught up thinking about the brands and wattage of the chips used for LED fixtures. However, the chips are not a good indicator of how well a light fixture is going to perform. There are many variables that influence the ultimate efficiency of any grow light fixture. Using the latest technology could allow for more efficient lights, but that is not always the case. Rather than focusing too closely on the components, it is important to consider the entire light system. The best way to evaluate the efficiency of the total fixture is by measuring PPF. To learn more about how much PPF you need, see our guide, "How Much Light (PPF) Do You Need for Indoor Cannabis?". If you have a grow light fixture in mind, use our Grow Light Calculator (Coming Very Soon) to evaluate the Usable PPF, efficiency, coverage, and harvest estimates it will provide.

COB Vs SMD

It is commonly believed that "Chip on Board" (COB) style LEDs are more efficient than "Surface Mounted Device" (SMD) style LEDs. However, this is not always true. COB fixtures use many individual light emitting diodes in close proximity to each other. This design can concentrate heat energy and lower the overall efficiency of the fixture. An SMD fixture can produce the same total PPF with fewer chips that are spread out over a larger surface area. The larger chips are less efficient, but the overall design may be more efficient because it allows heat to dissipate and avoids thermal runaway events. COB designs often offer lower price points and may be a great option for DIY fixtures but be sure to evaluate the efficiency of each fixture using PPF.

Quantum Boards: Printed Circuit Boards

The Printed Circuit Board or "Quantum Board" design has transformed the industry and is quickly becoming the standard for quality LED fixtures at the lower price points. These lights simply mount the diodes to a printed circuit board and use passive cooling to dissipate the heat. This streamlined design requires far few components and has allowed manufacturers to dramatically reduce the cost of high efficiency LED grow lights. Both the Mars TS series and the HLG quantum boards that we recommend take advantage of this printed circuit board design. See all our Grow Light Recommendations in our Equipment and Product Guide.