How Much Light Do You Need for a 4×4 Grow Room?
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If you grow your cannabis indoors, you need to provide lighting that emulates the natural one and can be manipulated a bit to maximize your crops. Buying the correct type of light (most growers prefer LED nowadays, though some stick to the good old HPS) is just a part of the process. After that, you use that tool to achieve the best results, which are easy to calculate and rate.
So, which LED grow light for 4×4 tent should you choose? And how do you install and use it correctly? Here are some instructions and tips on choosing and using.
Why Does It Accumulate the Light?
Like most plants, cannabis uses photosynthesis to consume light energy and transform it into chemical energy. This process allows the plant to function, grow, and accumulate nutrients that later become key elements of its buds (well, and other parts too). This is what we’re after, right? So light matters, and, in a sense, plants accumulate it. So they should have a good supply of it.
If you start with a 4×4 ft grow room, it’s quite easy to find a LED panel of a fitting size. But size isn’t the only thing that matters. There are also power, controllability, and technology. So, what should the light be for plants to accumulate it best?
The Calculations
Let’s assume you have just one plant per square foot (which is, anyway, the recommended density). It was found out empirically that the requirements of light for cannabis are the following:
- In terms of time, the plants need 18-24 hours of lighting a day during the growth phase and about 12 hours a day for flowering.
- In terms of wattage, a 4×4 LED panel should consume no less than 400 W (many of them use even more, so the perfect value is 500-650 W). This is enough to provide light intensity up to 1000 μmols and above (while the perfect number for cannabis is around 9000 μmols, you can never reach perfect precision, so a bit more or less will do too). if the appliance has a dimmer, that’s great because you can adjust the lighting.
- If it doesn’t have a built-in dimmer, check whether it supports external ones. A smart dimmer is better because it can be programmed to change light intensity at the right moments or turn it off and back on.
So, the conclusion is that you need to search for a 4×4 light panel with at least 400 W, with dimmer or external dimmer support. Though there are less powerful 4×4 lights (at 185 W, for example), we don’t recommend them for weed, because they are meant for other plants that require less light.
What does it mean in measurable or binary parameters that the manufacturer includes?
- The spectrum. It can be found in the specification of the light panel because it’s a crucial parameter. Take care that your panel has a white, blue, pink, and red light, which grants the best results for growing.
- The power (like described above).
- Dimmers and switches. These allow you to use the same light setup for different stages.
- Built-in fans. They are often there because they are necessary for maintaining the lights as well as for plant care.
Tips on Controlling and Changing the Light
After you got the best LED to grow light tent, you need to know that it’s not even half the job. You need to provide the right schedule of lighting. As the plant grows, so should the light time. When it’s fully grown and ready to bloom, you need to reduce the light hours to emulate the beginning of the fall and activate forming buds. This is better done with a controller that some models come with.
What you will also need is a fan or a cooler. Though LED lights produce much less heat than other types of lights, they still do. Luckily, there are models with built-in fans, so you won’t have to buy and install them separately.
- If the LED panel you use doesn’t have a built-in dimmer and doesn’t support external controls, you can just raise it higher to reduce the quantity of light the plants get. You should do it if the plants grow too high and the leaves close to the LED become brown.
- The distance between the lights and the top of the plant should be 12-18”. Yes, it means you will need to move the lights up as it grows.
- If you can afford it, you better have a backup light that will be necessary if your main one suddenly gets broken. You will not use the backup one for long, so it’s okay to have a cheaper HID setup instead of another LED one. Still, if you have multiple grow rooms, having an extra LED panel (like you use on all of them) will be better.
We hope it all grows well. You deserve a bit of relaxation after you have made a grow room and made it work. So let’s enjoy life in all the colors of the spectrum.