One of the essential elements a cannabis plant requires is light. During photosynthesis, a plant converts light energy into chemical energy, enabling it to grow strong and healthy, and with marijuana especially, light also fuels bud production.
When growing outdoors you can harness the power of the sun, however in an indoor setting, sunlight is mimicked through the use of grow light bulbs, which aim to present the same spectrum of light as the sun.
Grow lights enable you to control precisely how much light your plants get, making sure they get the same amount of light day after day, without the grower having to solve problems with poor weather or cloudy days that happen in an outdoor environment.
Some grow lights are more pricey than others, but also more efficient, saving money in the long run. Some lights are bulky with many parts, some light in weight, and some are better suited for young or mature plants.
There are many different kinds of lights out there, so it can be intimidating to know where to start. Right here's a guide to four basic kinds of grow lights on the market and the advantages and disadvantages of each.
Types of Grow Lights
There are several kinds of lights, but below are the four most common ones you'll see in a grow space. There are several variations within each of these four kinds also, and new lights and technology come out constantly.
Lights have components and bulbs, and some need a ballast. Depending on the type and model, the bulbs or the fixtures can be more costly. There are many acronyms, but don't be alarmed.
HID (high-intensity discharge) is an umbrella term under which MH and HPS bulbs fall, which we'll discuss more below. These types of lamps have a hood that reflects light and bulbs that are enclosed capsules containing a gas, as opposed to bulbs you 'd see in your home, which have a filament that heats up.
For HIDs, light occurs as an arc between two nodes inside the bulb. The gas contained in these bulbs is what makes MHs and HPSs different. HID bulbs are usually more costly than the reflective hoods that hold them.
HIDs have been the standard in indoor weed cultivating for years, but LEDs are quickly catching up to them. Both kinds of HIDs are usually affordable to purchase but will eat up electricity. HIDs throw off a lot of light and heat, which the plants need to grow and become potent. But, they run hot, contain heavy metals, and ballasts can fail.
Nevertheless, because of their low cost, if you're new to indoor growing and not sure how often you'll do it, you may want to purchase an inexpensive HID light in the beginning to test the water.
MH (Metal halide)
These bulbs have mercury and metal halides, generate a bluish light, and are commonly utilized for vegetative growth. They need a ballast to regulate the current. In the past, ballasts have been big and bulky, but digital ones are now available.
HPS (High-pressure sodium)
These HID bulbs usually contain sodium, mercury, and xenon, and produce a yellow/orange light, and also are generally used for flowering plants. Some cultivators will start off plants under MH bulbs and switch them to HPSs when plants go into the flowering stage, using the same hood. These lights also need a ballast.
CFLs (compact fluorescent lamps) are fluorescent lights similar to what you would find in a school or office building, but smaller. For growing marijuana, they are normally called "T5s"-- the "T" stands for "tubular" and the "5" represents its diameter, "⅝".
There are daylight bulbs and warm white bulbs; the former better for vegetative growth, and the latter for flowering.
These fluorescent lights are cheap and effective and good for vegetative growth. They're particularly great for helping along germinating seeds and tiny seedlings since they don't put off much heat and won't scorch the fragile seeds. They won't run up your electricity costs too much.
The drawback to CFLs is they aren't great for flowering plants, and cultivators will usually utilize another kind of light to finish plants. CFLs just do not generate enough strong light for plants to pile on weight.
Components are available in all shapes and sizes and can usually accommodate 4-12 long fluorescent bulbs; a standard size is 8 bulbs. Fixtures normally have a reflective material to bounce light in one direction, down on your plants.
LEDs (light emitting diodes) are fairly new to the cannabis cultivating scene, compared to HPSs, MHs, and CFLs, however they are quickly proving to be the way of the future. LEDs may be more expensive to buy initially, but they are far more efficient and kinder to the environment and your electricity bill. Some cities even offer tax breaks to commercial cultivators that install or switch to LEDs because they're much better for the environment.
LEDs also typically run a lot cooler than HIDs, so you may not require additional equipment to cool your grow area, and one LED can usually be used for both vegetative and flowering growth. Some high-end LEDs allow you to change the spectrum for each growth stage.
New LED grow lights emerge all the time, but knockoffs are all around. There are many cheap LEDs that do not produce the best spectrum of light for plants.