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what watt light bulb to use for growing weed

CFLs (compact fluorescent lamps) are fluorescent lights similar to what you’d find in a school or office building, but smaller. For growing weed, they are usually called “T5s”—the “T” stands for “tubular” and the “5” refers to its diameter, “⅝”.

How big a light you need will depend on the number of plants you plan on growing, but also on the size of your space. If you’re growing in a closet or a small grow tent, you’ll only be able to fit one small light in there. If you have a wide open basement, you could invest in a bigger light as opposed to two smaller ones.

There are many different kinds of lights out there, so it can be daunting to know where to begin. Here’s a guide to four basic types of grow lights on the market and the pros and cons of each.

HPS (High-pressure sodium)

One of the crucial elements a cannabis plant needs is light. During photosynthesis, a plant converts light energy into chemical energy, allowing it to grow strong and healthy, and with cannabis in particular, light also fuels bud production.

The first thing to consider before buying a grow light is how much money you want to spend. With more states coming online with adult-use legalization, homegrowing is becoming more popular and growing technology is getting better and more efficient all the time.

There are many types of lights, but below are the four most common you’ll find in a grow room. There are many variations within each of these four types as well, and new lights and technology come out all the time.

Ventilation

Another consideration with cost is that some lights run hotter than others—HIDs, for example—so they may require additional fans or an AC unit to cool down a grow space. Extra equipment means more electricity, also driving up your utility bill.

Power equals poundage, so if you want big yields you’ll need more wattage. Professional LEDs can start at as little as 200 watts, and go up from there. A high-watt light can double the work of several low-watt bulbs.

What watt light bulb to use for growing weed

If you get very high-wattage LEDs, you may need to vent out heat to keep the grow space cool

Cannabis plants under a T5 grow light – when plants are trained (like these ones in a Scrog setup) you can get pretty decent yields from fluorescents.

Pros and Cons of HID Grow Lights

Metal Halide grow lights are generally used for the vegetative stage because they produce a bluish light that vegetative plants love, though this type of light can also be used all the way to harvest.

Note: Some growers may have heard of “Induction” grow lights, which are pretty rare these days but still pop up from time to time. There are two types: “Magnetic Induction” grow lights do okay for growing cannabis but they’re pretty much glorified fluorescent lights. “Plasma Induction” grow lights actually perform pretty poorly at growing cannabis.

That being said, when it comes to the flowering/budding stage, if you can fit a bigger light you will get significantly better yields/watt by using an HID or LED grow light!

There are lots of options for grow lights that work well for growing cannabis indoors but in the end they boil down to 3 major types:

There is a larger size MH/HPS grow light available (1000W), but at that size it starts going outside the scope of a “hobbyist” grower as far as ease and yields. In addition to needing a lot of extra cooling which costs electricity, a 1000W HPS grow light is less efficient compared to a 600W grow light (as far as how much light is put out for electricity used). I think most hobbyist growers would be happier with a 600W, or even two 600W lights, over a 1000W

More Light = Bigger Yields!
(up to a point, it is possible to give your plant too much light!)

What watt light bulb to use for growing weed

The idea that we need 1000 watts to grow hemp comes from the days when it was common to use High Pressure Sodium (HPS) lights to grow anything indoors. At the time, HPS lights were the only decent artificial light source on the market, and a 1000 watt light was necessary for a sufficient photosynthetic light spectrum.

Let’s take a look at this short day plants-growing myth, and how you can grow indoors with eco-friendly (and wallet-friendly) LED grow lights.

Do you need 1000W to grow indoors? Not with LED Habitats Grow Lights

Yes. Much like a human sunburn, your plants can burn or bleach if you use too much light.

Where the myth that you need 1000W to grow hemp comes from

A lot of people believe that you need a 1000 watt artificial light to grow hemp indoors. The reality is, you can successfully grow medicinal herbs with far less wattage, saving you money on your electricity bill while growing healthier plants. So, how much wattage do you really need to grow indoors?