Certain things can happen in the grow room that most growers only consider once it happens. Once it happens, those growers will never forget. Having your lights fall and crush your healthy, striving, gorgeous-looking cannabis plants is an experience no one forgets.
In this article, we will fill you in with all the details, tips, and tricks for safely hanging grow lights above your precious indoor garden.
How to hang cannabis grow lights: The basic need-to-know
Hanging a new grow light is easier when gardeners have an empty grow space to work in, whether a tent, room, closet, or cupboard. How to hang a grow light will depend on a few factors. The size of the area, the size of the light, the heat signature of the light, and the weight of the grow light will all be considered in these recommendations.
Most growers are looking for a method to adjust the height of the hanging grow light without reconfiguring the setup. How to hang grow lights has become relatively easy, and the most common method used in the grow room is older than indoor cannabis cultivation itself. Tried and true, sometimes simple is the best way to be. However, there have been new advancements, including grow light hanging kits due to the popularity of indoor gardening. This article will cover your full range of options.
In a general sense, growers will want to position the grow light in the center of their grow space. Growers will want to have the ability to raise or lower the light, and they’ll need to be able to do this, even if the area is full of plants. Adjustments are not always possible in all situations, so we’ve broken down the best ways to hang plant lights in various growing situations.
How and where to position your grow lights
Grow tents come with a metal frame that forms the shape of the tent but is also used to hang equipment from. Most tents will have three support poles to hang equipment across the top. LED Grow lights often come with hanging devices, commonly in the form of ratchets. Attaching the ratchet hangers to these poles is how to hang LED lights in a grow tent.
High-pressure sodium (HPS) lamps are not ideal in small tents due to heat, but they would also be suspended from the same poles. While LED grow light fixtures can be positioned within inches from the edge of the tent, HPS systems must be given more room. When hanging this type of plant light fixture, it is recommended to have at least 12” of clearance on each side to reduce the fire hazard.
A special consideration with grow tents is the weight capacity of the frame. Manufacturers will give a recommended weight limit for the tent frame. Consider the weight of all the gear hanging from the support poles. Typically inline fans and carbon filters are suspended here as well. When hanging a plant light fixture, you must be within the maximum weight allowed. Growers commonly forget to account for the added weight on the frame of the negative pressure created by an inline fan and a sealed tent, aka when the side walls suck in.
Want to know how to build a DIY grow tent, Check out our guide to learn more!
DIY grow room
When your plants grow in a DIY environment, it provides many options for creative ways to hang grow lights. However, keep in mind when hanging grow lights from the ceiling, the mount must be firmly attached to a ceiling stud. The hanging grow light should be given adequate space between the top of the fixture and the ceiling to allow for airflow, which aids in cooling.
If you use multiple lights in one room, lay the configuration out on the floor before attaching your first light. Does each light have a joist (support beam) above it in the ceiling? If not, the obvious question would be, how to hang grow lights from a ceiling that doesn’t have a joist above it?
Here’s how: Use a 2×4” piece of wood that spans the area between ceiling studs. If you’ve measured your studs, but your light placement doesn’t align, this would be how to move a light fixture over a few inches when suspending them from a ceiling in a DIY grow room. The other option would be to shift the light placement to align with the studs. (I’ll go into further detail on how to do this later on in this article)
With the advent of tents, fewer people are growing directly in closets. Some growers opt for a 2×4’ tent, which fits the footprint perfectly of most closet spaces and has support bars to hang grow equipment from. LED lights for a small closet grow room setup is ideal, followed by a combination of CFL bulbs. HPS fixtures are too hot for the confines of most closet grow setups.
If using a closet grow setup with no tent, there are still a few options for hanging a plant grow light. The pole used to hang clothes makes an excellent location for a grow light hanger. Like a DIY grow room setup, you can attach a hanging plant light to the ceiling, providing a stud is available.
Height is always a challenge in these styles of growing. Because of the compact nature of micro-grow spaces, lights should not have a long hanging system attaching them to the top. Instead, lights are often mounted near the top while allowing some space for heat to dissipate and air to flow. Only low-wattage, energy-efficient LED lights or CFL bulbs are recommended for this growing style.
In cupboards, growers can add a closet pole (shortened, of course) to hang lights from. If the top of the cupboard is stationary (not a drawer that pulls out), you can use small J-bolts. These screw into the wood above, and lights or cords can be attached to them. We advise against adhesive grow lights. Although the light they support may be lightweight, moisture and heat can weaken the adhesive bond.
How to hang grow lights from the ceiling
- Lay the light(s) on the floor where you wish to hang them. Put a piece of tape on the floor where the hangers would attach. Remove the lights so you don’t damage them.
- Locate the ceiling studs using a stud finder. Mark the center, which should be every 16” in the US or 400mm in the UK.
- Visually confirm if the tape on the floor is aligned with the studs. You can be exact using a piece of string long enough to reach the floor from the ceiling. Tape or tack the string to your mark for the stud and pull it down straight.
- If they align, great. If not, you could
- A) move your lights to align with the studs, OR
- B) use a 2×4 to span the distance between the nearest studs aligning with your desired hanging position.
- Measure the distance from one hanger connection point of your light to the other. Mark these measurements on the ceiling stud or 2×4. Remeasure your light; remeasure your ceiling marks. Drill a starter hole for your fasteners.
- Use proper fasteners. You don’t want a screw that only penetrates the stud 1/4”. You should aim for at least 1” of screw thread penetrating the surface you are attaching to. You can use chains, ropes, or ratchets, often connecting a J-bolt into the studs or 2×4. Buy commercial-grade fasteners, don’t use wimpy items. The costs are low enough to get the proper material.
- J-bolts make it easy for a grower to slip on or off the hanging system to adjust the height. I prefer the rubber coated, 4” J-bolt. Growers who use ratchets with clips to hang grow lights can also use an eye-bolt mounted into the stud. To adapt an eye-bolt for use with chainlink, try an S-hook.
- Connect the hanger of choice and lower it to the floor. Attach the hanging system to the light and raise the light to the desired height.
How to hang lights in a grow tent
- Measure the distance between the connection points on your grow light.
- Position the support bars at the top of the tent to the distance you need. It is best to spread the weight between two bars instead of attaching the light to just one.
- Attach your hanging system to the bars. Lower the connecting side to the tent floor.
- Connect the light to the hanging system and raise it into position.
**Ratchet-style hangers are the most common method for hanging grow lights. To attach these to the support bars at the top, wrap the clip over the bar and attach it to the same cord on the other side of the bar. Pulling down will tighten the hanging clip and cord against the support pole. The bottom side of the ratchet can now be used to lower or raise the hanging grow light.
How high should grow lights be above plants?
We’ve mentioned several types of lighting so far, HPS, LED, and CFL, each with a different heat signature. Similarly, each of them will have different light intensity, which will also vary by wattage within the same type of light source. Flowering plants need intense light, while seedlings need very little. All of these factors contribute to how high to hang your grow lights.
|Distance from Plant Canopy(meters / inches)||Intensity (Lux)||PPFD / PAR(μmol/m-2/s-1)||Coverage or “Light Footprint”(m² / ft2)*|
|2m / 79 inches||955lx||670||7.6m2 / 81.8ft2|
|1.5m / 59 inches||1692lx||1170||5.0 m2 / 53.8ft2|
|1m / 39 inches||3663lx||1670||3.0 m2 / 32.3ft2|
|0.5m / 20 inches||12,500lx||2170||1.5 m2 / 16.1ft2|
|0.2m / 8 inches||50,300lx||2670||0.5 m2 / 5.4ft2|
* Coverage will vary based on the grow light being used. LED source shown here does not use a reflector to direct the light
We’ve created a grow light distance guide for each light source to answer this question.
What do you hang grow lights from?
HPS systems often have dedicated holes to attach a clip or hanger that can be clipped onto. Many LED lights have holes to clip into, but some come with a harness that attaches to the light. The harness is then attached to the hanging system. These harnesses usually consist of smaller clips that attach to the light, which are also connected to fixed-length steel wires. Those wires reach from each corner of the light to one central point above for attaching.
Ratchets, by far, are the most common hanging system. Many lighting manufacturers include a set in the box, and buying ratchets separately costs little. Ratchets are also very easy to attach and operate. This device features a clip attached to a cord; this cord enters a small plastic box with a ratchet inside, which controls the cord length. The cord continues out of the other end of the box, where there is another clip. One end attaches to the fastener or pole, the other to the grow light.
Combining J-bolt fasteners and chainlink has been a popular option when hanging grow lights for indoor plants. This is primarily for people in DIY grow rooms who are attaching grow light hanging devices to the ceiling. Using this style, growers gain the ability and uniformity of raising or lowering the light a set number of links each time. Some growers will color certain links to avoid the need to measure their adjustments.
How do you hang grow lights on a budget?
Fortunately, the ratchet-style hangers are inexpensive. Growers can find a pair of them available for $6 to $15. Don’t be tempted by the cheapest pair; remember, these grow light hangers keep your grow lights from crushing your crop.
Growers with powerful LED lights with dimmers can adjust the dimmer instead of raising or lowering the light. In both cases, the goal is either more or less light intensity on the canopy. Growers can use a fixed-length chain, cable, or rope attached to the ceiling or support poles.
Grow light lift systems are sometimes used in the commercial environment but rarely on the home or hobby level. A series of small motors are attached to an overhead-mounted rail, and a metal wire attaches to the light fixture below. With a touch of a button, the lights will raise or lower. The cost of a light lifter system is enough to rule this out as being feasible for home garden spaces.
Final thoughts and tips on hanging grow lights
Redundancy will make you feel better. Some growers will attach two of the ratchet hangers on each connection point. If one ratchet fails, it will not cause the light to come falling due to redundancy on that connecting point. I use a fixed-length cord that equals the lowest setting my light gets above the canopy. If my ratchet were to fail, the fixed-length cord would stop the light from falling into the plants.
This can be especially important for lights with one connection point on either side. If one of those two sides fails, the light will swing like a pendulum into the plants. When lights have two connection points per side, if one ratchet fails, three points still hang right. Failures are rare, but they can be catastrophic when they happen. Make sure your ratchet of choice supports the weight of your grow light.
Hanging lights can take less than five minutes once you know how to hang grow lights in a tent. DIY grow rooms and closet/cabinet grows may take a few minutes more because you need to locate studs and mount fasteners, but the process is straightforward. Hanging grow lights is a task that growers of all experience levels can handle. Don’t be intimidated; you’ve read this article. Hang those lights and get growing.
If you are just starting your grow journey, check out Robert’s Grow Bible. It has all the knowledge, tips, and tricks to get you to your first harvest and beyond. Enjoy it at your own pace; the download is free and can be shared with your grow buddies. Did we miss any of your favorite grow light hanging techniques? Please let us know in the comments. Happy growing!