Using a Grow Light Rail to Increase Indoor Marijuana Yields One of the benefits of growing marijuana outdoors is sunlight. The movement of the sun allows each plant to soak up plenty of beneficial rays. Indoor growers can mimic this movement to the benefit of their plants.A light rail is a mechanical track used to move an HID light over a garden. When grow lights are stationary, especially HIDs which can get hot, it is easy to burn plants. There are also parts of the grow room that stay shaded. Cannabis plants in these areas won’t grow as vigorously as their neighbors sitting directly under the light. You can eliminate hot spots and shaded areas with a light rail. The movement of the light will increase your coverage by up to 140%.Can a Light Rail Replace a 2nd Light? If a light rail boosts coverage so significantly, could you add one instead of purchasing another light? It would certainly save on electricity.But there is some math you need to do in order to make a smart decision:You want at least 50 Watts of light (using an HID) per square foot of growing space. Less if you are using LED grow lights. To calculate the amount light reaching your plants using a light rail a decent formula to follow is this:Total Watts from HID light X 1.4 (140% light rail coverage) Let’s do an example:You are using a single 600 Watt HID grow light. Your grow area is four feet by four feet, or sixteen square feet (16 sq ft) in all. If you add a light rail, do you need a second light?Using our formula:600 Watts X 1.4 (140% light rail coverage) = 840 Watts of coverage. If you have 16 sq ft, this equates to 52 Watts per sq ft. Remember, 140% increase in yield is on the high side. You may only see an increase of 125% depending on the light rail you choose. Even so, you would get 46.8 Watts per square foot.In this case, yes. You could get a light rail instead of another light.What if you had the same set-up with 1000 Watt light and a 36 square foot grow space? Managing a Light Rail in your Grow RoomThere are a couple of logistical issues to consider when you put up a light rail.1. First you have to choose the type of rail. There are two basic designs:A horizontal sliding rail that moves the light back and forth over the gardenA spinning rail that looks somewhat like a ceiling fan and moves in a circular motion over the grow space. You can also get a smart rail, which pauses at each end.2. Cords. Think about how you will secure the cables from the lights and the rail so they don’t get caught as the light slides back and forth.3. Secure the light rail to something sturdy. Those lights are heavy! You can try attaching it to a 2 x 4 and then to the ceiling for extra stability.Our Two Favorite Light Rail Systems1. The Agra Mover The basics The Agra Mover is an industrial light rail. It is cheap and it is strong. Getting an Agra Mover is like buying commercial kitchen equipment. It is better than the stuff from the department store and costs less. No thrills, no bells and whistles, just high quality materials that work well.Where to Buy One? You can only order the Agra Mover online at the company’s website.What People are Saying about the Agra Mover These light rails are getting great reviews. The features people love include:Super Tough. The main problems with light rails is that the bearings wear out, but these ones are extra sturdy.They cost about $200 .They support multiple lights. Be sure to use a heavy duty spring.Stellar customer service. The owner is always available to troubleshoot or fix problems.ReBuild Kit If you plan to use your light rail heavily, with multiple lights for example through several grow cycles a year, consider purchasing a rebuild system. The kit is affordable and allows you to easily restore a worn out Agra Mover yourself.2. The Lightrail 3.5 IntelliDrive The basics This is a simple, sturdy light rail. It moves lights across your garden at a speed of four feet per minute. It has extension options to cover large areas, and is a smart rail with adjustable pause times at each end.The Facts – Available at Amazon The standard IntelliDrive is six feet long. It has stops so you can shorten the distance the lights move if you need to. Here are some features we really like about the IntelliDrive:Extension options: add another six foot rail and run it from the same motor to add another lamp OR add a three foot extender rail.10 RPM motor runs strong3. The LightRail 5 Complete KitThe basics With a high torque 4 RPM motor the LightRail 5 is heavy duty. This 8 foot long rail has a 90lb+ capacity when properly balanced to handle heavy HIDs.What People Are Saying About the LightRail 5 This one gets rave reviews. Here’s why:You can use multiple reflectors thanks to the high weigh capacity of the rail.You can easily hang two lights from a single rail.It is completely silent for extra stealth.One reviewer got a 20% higher yield out of his cannabis crop using the LightRail 5.Do You Need a Light Rail? A light rail is a great way to maximize your light coverage. You are spending good money to run your HIDs. Even if you can’t avoid purchasing a second light, using a light rail will increase the amount of light reaching your plants and will boost yields. A good system is a relatively small investment when you consider all the extra, resinous buds you could grow.For nearly any indoor set-up with HID lighting, a light rail is an investment that will pay for itself.