Light Deprivation: Methods | Tarps |Suppliers

Agratech black out
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If you read part one and two of this light dep conversation then you should understand the process behind it and some of the pros and cons associated with it. If you’re considering taking the next step towards extra harvests and higher quality buds, here is a post with tons of videos demonstrating the methods for blacking-out a greenhouse, quick descriptions of some blackout tarps, and a video of Forever Flowering’s Breathable Wall accessory.  

Assuming that you already have a greenhouse, the next step is to figure out how you want to accomplish the task of blacking it out. Below are a handful of videos (starting with manual to motorized/automated) demonstrating different styles and methods for blacking out a greenhouse.


Pull a tarp over your greenhouse everyday:

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Or you can upgrade and use an assisting tool like Gro-Tech Systems Helping Hand:

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Motorized light deprivation systems:

FullBloom Hydroponics Evergreen Automated light dep. (Roll down style):

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Engineered Greenhouses motorized light deprivation system. (Pull up style):

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Forever Flowering rectangle automated greenhouse. (Slide ceiling and drop walls):

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AgraTech North Slope 30 greenhouse paired with Forever Flowering light dep. (Slide)

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If you’re blacking out a simple hoop house then all you really need is a blackout tarp and maybe something like Gro-Techs helping hand tool. If you plan to go automated, then you are going to want to do a little research into which light dep systems pair best with your greenhouse. The motors for these systems are small and slow, but they have some serious torque. I have heard stories of systems slipping off track and destroying themselves because they were never lined up to fit properly with the greenhouse they were paired with. It is important to remember that these systems and methods also vary significantly in cost.

Blackout Fabric

Once you figure out which method you prefer, then you need to start looking into the different blackout fabrics. Below are a few descriptions of blackout tarps sourced from American Cover  and Forever Flowering:

There are four primary types of black-out light dep covers currently on the market.

  • Panda is a Black/White polyethylene film that is typically 4-6 mils thick. The cheapest, by the least reliable in an outdoor greenhouse. The material is too thin to completely block light, and it can easily be ripped.
  • Woven Coated Poly Black/White is a non-stretch woven material coated with white poly on one side and black on the other side, usually 9-12 mils thick. Heavier tarp with superior tear resistance, but most woven coated poly covers contain pinholes that can allow light to enter. They also have UV inhibitors that prevent premature aging, but once that wears off it will be a less effective light dep cover.
  • Breathable light deprivation covers are made from layers of Black and White fabric not polyethylene sheeting, available in 6-30 mils thick. One of the most expensive tarps, but these are designed to be used on the inside of the greenhouse and allow airflow to reduce heat and humidity build-up. However, if it gets wet it can be an ideal environment for mold to grow.
  • BOLD is a string reinforced polyethylene film with a solid white and solid black side, without pinholes and 8 mils thick. Lightweight cover without pin holes that can block 100% of light. Tear resistant non coated cover that should last through a few growing seasons.

Blackout covers offered by Forever Flowering:

Triple layer Breathable Blackout Fabric: Black on one side white on the other to deflect excess heat from the sun. Ideal for inside of the greenhouse automated blackout systems.

Non-Breathable Blackout Fabric: Light weight easy to work with blackout tarp that is ideal for a manual light dep system. Use in conjunction with the breathable wall for proper airflow.

Light dep Accessory:

Forever Flowing Breathable Wall:

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“Move the air without the passage of light.” Brilliant bolt on fan cover that allows airflow but still blocks light from entering the grow area. Allows the grower to battle the humidity issues associated with an inside automated light dep system.

Now that you have read Light Deprivation: IntroLight Deprivation: Pro vs. Con, and  this post, hopefully you are on your way towards gaining multiple high quality harvests. Some other topics you might want to consider is supplemental lighting, intake and exhaust fans, and proper electricity. Many companies are starting to offer complete light dep packages (greenhouse, light dep system, etc.) which should simplify the purchasing process.

If you are truly considering a light dep system the best thing to do is physically stop by or give one of the suppliers a call. Forever flowering has been a great source of information for a few of my close friends, they can be reached here.

Do you have any experience with this topic? Any opinions on the companies that offer light dep? Please share your thoughts in the comment section below.

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