Positioning Your Cannabis Grow Light
Where To Put Your Cannabis Grow Light?
When growing cannabis indoors it’s very important that you make the most of your your light, after all you are paying for it so why would you want to waste any. If you intend on making the most of the space you have to use then the information below may be very helpful to you.
How much light should i use?
A 400 watt grow light will cover a 3x3ft space.
A 600 watt grow light will cover a 4x4ft space
A 1000 watt grow light will cover a 5x5ft space.
Although it’s the amount of light that mainly determines the yield of a grow you should remember that using too much light in a small space will more then likely cause excess radiation and make the grow room to get too hot for the plants, both of these are going to result in a reduction in yield. Maintaining healthy plants is the key to a heavy yield.
How close should i keep my lights to my plants?
A 400watt lamp should be kept 30cm(1 foot) away from the plants canopy.
A 600watt lamp should be kept 45cm(1.5 foot) away from the plants canopy.
A 1000watt lamp should be kept 60cm(2 foot) away from the plants canopy.
A way you can test to see if the cannabis grow light is too close to the plants is to place the back of your hand below the light for 30 seconds, if your hand gets hot then you know know that distance is too close for the plant. If the light is too close to the plant you will notice that the leaves will begin to curl up, this is because when a plant gets too hot it can not hydrate itself fast enough and begins to dry out. Another thing you may notice if the light is too close to the plant is a fluorescent yellow colour on the tops of the buds or leaves, this is caused by excess radiation from the light and will slow growth dramatically. As plants grow you will need to raise the light to maintain the correct light to plant distance, you can hang a weight from your light on a piece of string that is the correct length to help you do this.
If you are using an air cooled light shade then you can put your light alot closer to the plants, As the light passes through the glass screen of an air cooled shade the lumens are reduced by around 20%.
So if you do happen to be using an air cooled shade you will still need to place the back of your hand under the light for 30 seconds to test out if it’s cool enough at the plants canopy. I advise you to keep an eye out for any yellowing tops and leaves because although it may seem cool enough at a particular distance the light might be a little bit too intense for the plants.