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How to Reduce Greenhouse Light Pollution

In many places in N. America and Europe, residents are complaining about light pollution, in the form of bright purple lights covering the nighttime sky.

These strange lights aren’t a mystery, they come from greenhouses. Most commonly, cannabis greenhouses. These complaints are now moving many counties and towns to regulate greenhouse light pollution.

Luckily, reducing light pollution from greenhouses is actually pretty simple. The cannabis industry, which is well-versed in adapting to regulations, will without a doubt manage this hurdle.

Greenhouse Grow Lights Cause Light Pollution

Greenhouse light pollution is a relatively new issue. This is due to two changes in the greenhouse sector. The first, is the rise of greenhouse cannabis cultivation. Cannabis requires a highly specific lighting regimen. For the early vegetative phase, it requires 18 hours of full light, and only 6 hours of darkness, per day. Some growers even choose to keep the lights on 24/7 during early stages.

The second change to the industry, is the widespread use of LED grow lights. LED is much more efficient than traditional HPS, making it more feasible to keep the greenhouse lights on, as much as necessary.

As greenhouses are designed to let sunlight in during the day, it’s inevitable for light to escape during the night. This raises concer

What Is Light Pollution?

Light pollution is exactly what it sounds like – excessive use of artificial light, which harms the environment. But why is light a problem?

Too much light in the environment during the night has many negative effects. First, it affects the ecosystem.

Animals and plants rely on nature’s cycle of night and day. Excessive light can disrupt wildlife navigation and feeding, having negative consequences for animal populations. It also disrupts the growth and development of wild plants in the area, which also require darkness during the night.

The second problem with light pollution, which is the main reason for the regulatory changes, is the impact on human health and psychology.

Excessive light exposure during the night has adverse effects on our brains. It inhibits the production of melatonin during sleep, and is associated with increased fatigue, headaches and stress. The American Medical Association has also acknowledged the negative impact of light pollution.

How Can Growers Reduce Greenhouse Light Pollution?

Cannabis growers won’t stop using grow lights during the night, as the plants require it. Luckily, reducing greenhouse light pollution isn’t a complex issue, even with the lights on. Basically, it’s all about restricting light from escaping.

Reducing light pollution simply requires growers to install retractable blackout screens and window coverings.

This is an investment most growers aren’t quick to make, understandably. But in fact, it holds more benefits for growers than just compliance with regulations, and it can pay for itself in time.

Using a blackout screen and window covers increases the greenhouse’s insulation, reducing the heat transfer with the outdoors. This helps to maintain warm, optimal temperatures inside, by avoiding unnecessary heat loss, which is a major energy expense.

Solving the Greenhouse Humidity Problem

The most common problem holding growers back from sealing their greenhouses is humidity.

In a closed greenhouse, humidity inevitably rises. This is especially true overnight, when it’s colder and the air can’t hold as much water vapor, increasing the relative humidity.

The best solution to this issue is to use dehumidifiers to control humidity during the night. Dehumidification is also much more efficient than ventilation in reducing humidity, and is possible when ventilation isn’t, like when it’s humid, raining or extremely cold outside.

By incorporating blackout screens and dehumidifiers, you can get multiple benefits – avoid light pollution, maintain low humidity and save energy, all from within the greenhouse.

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