Lights!
For this home grow, I’m using a set of metal shelves in my office. They are ordinary Whitmor shelves, like you might find in Costco or Target. I like them because the shelves are easily movable, making it easy to keep the correct distance from the lights as the plants grow. I started with one 125-watt Fluorowing compact fluorescent bulb. Later I added two 60-watt CFLs at the sides. This gives roughly 10,000 lumens in my three square foot growing space, with much of the light concentrated under the larger 125-watt bulb.
This is a minimal amount of light for the space. I have roughly three square feet of shelf space, and up to six feet vertical space. Marijuana plants want as much light as they can get, and the more light the better your bud production will be. With a total of 245, I have roughly 80 watts per square foot. If you used LEDs you could double that and the plants would be happy. LEDs are pricey, though. My own plan is to replace the 60-watt circular CFLs with a second fluorowing and use the circular CFLs in a cloning area once I get one set up.
I notice a definite increase in the electricity bill when I am growing even with these efficient bulbs. They also put out more heat than I would have expected, which is nice when it’s this cold out, but not so pleasant in the summer heat.
Originally we hung the lights from shelf brackets mounted with some sturdy wall drillers. But they couldn’t handle the weight, and after I had a near-accident when the wall mounts failed, Mr. J built me this extremely sturdy wooden frame that fits around the shelving unit. It is bolted to the wall and reinforced with metal brackets. We put an assortment of eyehooks at intervals to string chains from. Using S-hooks, it’s easy to move the lights up and down as needed.