10 Common Lighting Mistakes in Cannabis Cultivation

Supplement - lighting up the cannabis market

February 6, 2017

1. Ignoring the manufacturer’s recommendations for use. Talk with your lighting supplier, digest the user manuals for lighting choices and learn how to adapt to them. For example, some lighting fixtures are optimized when mounted closer to the canopy than other lighting fixtures. Failure to deploy the fixtures as recommended can result in wasted light and lower light intensity.

2. Placing too much faith in manufacturer’s performance claims. It’s difficult to get a true representation of comparative performance on many products. Be skeptical. Ask questions. Whenever possible, test multiple fixtures before making a purchase decision for your entire operation.

3. Overemphasis on lighting’s impact on success. Temperature, humidity, C02, lighting and watering cycles fit together like pieces of a puzzle. If one factor is out of sync, it can have a noticeable effect on yields. Precise indoor climate control can help maximize lighting efficiency, but a lighting system alone does not render magical results.

4. Failing to swap HPS bulbs often enough. Consider changing bulbs at least every third harvest. Old bulbs are inefficient and provide poor light quality for photosynthesis.

5. Not knowing your energy capacity. Some growers don’t consult an electrician before making purchases. Or, they buy products based on erroneous assumptions. Know your building’s amperage and voltage when installing lamps, fans, pumps and other equipment that affect power requirements. Most manufacturers publish their products’ electrical consumption, so it’s a good idea to make use of them.

6. Failing to consider how lighting requirements change during a plant’s life. A clone’s need for spectrum and light intensity are far different than that of a mature plant. Growers need a lighting solution for each growth stage. Finding the correct formula may require multiple vendors, extra research and testing, but the impact on your profitability makes the work worthwhile.

7. Lack of technical knowledge. Light and photobiology are highly technical subjects, often informed by confusing metrics. Without proper knowledge, growers may base buying decisions on sales pitches rather than facts. Stay up-to-date on the latest horticultural research, such as from the International Society for Horticultural Science, which provides books and access to online articles. Also review third-party research on lighting types and attend trade shows.

8. Being an early adopter. The latest technology is a lure for growers who like to believe they are onto something better. If you try new technology that has no track record, always test it on a small-scale before you roll it out.

9. Assuming higher wattage means a better light. The question to ask is how much light is emitted by a fixture, as light is what fuels photosynthesis and plant growth. Wattage accounts only for the amount of energy going into a fixture; photosynthetic photon flux (PPF) is the amount of light (specifically photosynthetically active photons) a fixture emits.

10. Using products that aren’t designed for commercial operations. Many retail or consumer-grade products are marketed to commercial growers. These products are not suitable for commercial use. Look for manufacturers that provide applicable and accurate product performance data and proof of integration in horticultural operations.