When it comes to growing cannabis, light is your veritable plant God. Naturally, this means that you want to use absolutely as much of your hydroponics light as you possibly can. After all, waste not want not, as they say. But light naturally bounces off your plants and likes to spread out all over your grow room, becoming more diffuse in the process and failing to do its job by going to the plants.
Before you despair over all the lost light, though, there are many tools you can make use of to reflect and return as much of your light as possible back to the plants. One of the easiest, and cheapest, ways to increase total light use in your grow space is to paint the walls flat white.
White naturally reflects light, so if you can’t afford to do anything else, at least paint your walls with a fresh coat of bright white paint, it will act as a natural reflector for your plants. It might sound incredible, but having the right reflective material on the walls of your grow room can increase the amount of light your plants receive by up to 30% or more.
Ensuring that your walls and floor are nice and reflective also increases the total amount of light that your plants receive beneath the canopy. Some of the greatest materials to use for increasing the reflectiveness of your grow area include:
- Mylar is a highly reflective polyester film. It comes in several thicknesses, most commonly 1 mm and 2mm thick. Although Mylar is highly reflective, it does tear easily (the 2 mm thick Mylar is markedly sturdier) and it can’t be washed easily. Unfortunately, Mylar will reflect heat as well as light, so you’ll need cooling in your grow area.
- Foylon is a much more durable version of Mylar, with very similar reflectivity. Made of polyester reinforced with a foil laminate, Foylon is resilient enough to be cleaned and is most popularly mounted to the walls with Velcro, making removal for cleaning easier.
- C3 anti-detection film is another specialized version of Mylar. With reflectivity rates of 90% – 97%, C3 anti-detection film is also up to 90% infrared proof, protecting your grow from unwanted discovery by infrared scanning technologies. Like the other versions of Mylar that are available, C3 film will also reflect heat, so you will need cooling.
Some of you, especially those on a budget, might be tempted to use foil as a reflector. Although this is possible, keep in mind that foil is only about 55% reflective, compared to the 90%+ reflectivity of Mylar and Foylon. If you do choose to use foil, be sure that the dull side is what faces your plants, not the shinier side.
Exercise caution if you choose to use foil, as well, since hot spots can form quickly. In combination with HID lighting, foil may pose a serious risk due to its electrical conductivity.
Distance also causes your lumens to dissipate throughout the grow area, so minimize distance as much as you can without burning your plants, and add a reflector / hood to make the most of your light. You can also add an air-cooled tube or sleeve to your light so that you can put it closer to your plants without burning them.