Now we are going to get pretty darn technical, and explain some stuff that you need to know. When lighting marijuana grow room, you are trying to imitate the intensity and coverage of the sun in said grow room. Depending on the part of the country you are in, the sun at high noon in summer pumps out between 8000 and 10,000 lumens per square foot. These figures are based on a whole lot of environmental factors, so please accept them as averages, and not absolutes.
What precisely is a lumen, and how does it matter for my cannabis grow?
A lumen is a basic measurement of visible light, which does not translate into usable light. A lumen of usable light is a base measurement of how much light can be used to make chlorophyll by that marijuana plant. Chlorophylls are the most basic building blocks for a plants growth and capacity to grow, the plant manufactures chlorophyll through a chemical process within the plant that converts light into a growth substance. Sort of amazing in a very plant-like way. Subsequently, the more light, the healthier, bigger, and stronger your plant will grow. That is why it is so imperative to give your indoor marijuana grows all the light they can possibly handle, and then some. There is almost no such thing as too much light in the grow room, although finances and heat stability might limit that factor. It might make sense to use a mixture of HID lights and some of the higher end LED lights in order to introduce a lot of light into t grow room, without the commensurate heat and drying out issues.
LED’s as a secondary light source in the marijuana grow room
Some of the LED’s work well as a secondary system in a predominantly HID system. They burn cooler than the HID’s, and offer a slightly wider spectrum of available light for your baby marijuana plants. I do not recommend them as a sole light source, rather as an additional source to your HID lights. Yes, I will use LED’s as an adjunct to HID lights, but never as a main lighting source. There are a couple of really good ones out there, I do recommend the 600 watt LED lamp from the Grow Goddess as a great additional lighting source for the grow room.