For years, “grow bulbs” we’re just the same bulbs in a street lamp, but marketed as horticultural bulbs. Only until recently have specific spectrum bulbs been available to the public for growing plants.
The basics are simple; you need a bright light to grow big, healthy plants. There’s plenty of different light options, but the costs may outweigh the benefits depending on how much you want to spend. The minimum we recommend to fully flower a plant is 315 watts.
If you want to skip the list and are just dying to know what light you should get, a common choice is an HPS light from 400 to 1,000 watts. 315 CMHs are very popular too. If you want best of the best, look for a double ended 1,000 watt light. Do you have no idea what those letters mean? Then read on!
Even if you’re new to growing, you should still be familiar with this kind of light. Fluorescent bulbs can be found in most home stores, and can be used for growing or just general lighting.
Fluorescent bulbs are energy efficient which can save on the electric bill. CFLs (compact fluorescent bulbs) are one of the most common types, and are most recognized by their twisted shape. Due to their small size and energy output, CFLs are usually kept much closer to plants for better coverage.
T5 lights are also popular and easily available. T5s are bigger and wider than traditional CFL bulbs, giving them more coverage, but they can still be kept closer to plants.
Fluorescent bulbs are popular because they are cheap, save on electricity and are better for short spaces, while still providing a great light spectrum for growing. However, you will get smaller yields compared to other lights like LED or HPS, and fluorescent bulbs don’t penetrate as deep, making them a poor option if you have taller plants.
High intensity discharge lights are more efficient than fluorescent, with a little more leg work put in to set them up. HID lights put out much more heat, which increases the chance of overheating or burning plants if kept too close.
Most HID lights are screwed into a reflector or hood to reflect more light. Due to the higher heat output from HID lights, growers will usually attach an exhaust system. This way the heat can be vented to prevent overheating and burning.
There are a bunch of options when it comes to HID lights, from LEC (Light Emitting Ceramic) and MH (Metal Halide) to HPS (High Pressure Sodium) and CMH (Ceramic Metal Halide). MH lights will be cooler and more useful during vegetation stages, while LEC lights act as a middle ground between MH and HPS.
HPS lights are often used during the flower stages, as their yellow light can stimulate flower production. Due to this, HPS will usually produce bigger yields than any other light, making HPS one of the most popular options for growers.
CMH (also referred to as LEC (light emitting ceramic)), most commonly the 315 CMH, uses ceramic like HPS, but covers a smaller area. However it will still cover a wide enough area if you’re a hobby grower with just a light or two.
LED lights are usually the most expensive, while rarely saving any real noticeable amounts of energy per square foot. They are a popular alternative to HPS lights, but lack the spread and wattage compared to other options.
Beware that HID lights will get much hotter than other options, and usually require more set up. With a bulb, fixture, ballast, extra cables and exhaust one can see how this can be a more expensive option that tends to scare away newer growers. But if you want the highest yields at the cost of additional equipment and little bit of a learning curve, HID lights are the way to go.
When it comes to choosing a light, you can never be too picky. With the wrong light, you can seriously damage your plants if you don’t know what you’re doing. With the right light you can seriously damage your plants if you don’t know what you’re doing. But with the right light and a little bit of knowledge, you’ll see great yields.