How to Set Up an Optimal Grow Tent for Cannabis

Are you thinking about growing your own cannabis and not sure where to start? When you’re growing indoors, you will need to create an optimal environment for your cannabis plant to grow well and produce quality flowers. Grow tents are self-contained environments that allow you to have direct control over the variables affecting your plants. This guide outlines all the items you need when setting up your grow tent and some tips that I’ve learned from growing my own cannabis over the years. 

Where to Setup Your Cannabis Grow Tent

Where you set up your grow tent will depend on a few factors like your available space, the type of tent you are using, and the amount of light and airflow in the space. For my grows, I keep the plants in my basement because that is where we have extra space to fit our tents (the largest being 5x5 feet). Our basement generally stays on the cooler side, but we don’t have air conditioning available, so it gets very hot during the summer. Although these weren’t the ideal temperature conditions, the room had space available, had little to no light, and was easy to get airflow in. There are techniques you can use to help with certain issues if you don’t have the perfect space to setup (which most people don’t). During the summer, we try to grow plants that tolerate heat better since our tent can get up to 85F when the lights are on. I also lower light intensity, which can lower the overall temperature of the tent. Where you setup your grow space will be different for each grower, so choose the space that seems the most ideal for the majority of time that you’ll be growing. 

Choosing your Cannabis Grow Lights

Lights can make or break your grow. Alongside genetics, they’re one of the biggest factors determining how good your end product will be. There are three main types of lights to consider for indoor growers.

High Pressure Sodium (HPS) and Metal Halide (MH) Lights

Both HPS and MH are types of High-Intensity Discharge (HID) lights. They release a high amount of heat from their bulbs, often requiring an air conditioner for the grow space to regulate temperature. Some say that many older strains grow better under HID lights, which is possible since those plants were initially chosen and preserved under that light source. HPS and MH lights are often used in tandem since they work together to create a broader light spectrum.

LED Lights

LEDs have taken off in popularity in recent years. They are more efficient and the heat they produce is small compared to HID lighting. LEDs generally have a longer lifespan and can capture different light spectrums beneficial to the plant (which HID lighting cannot do). LEDs are my preference for lights and a great choice for a beginner grower. 

Fluorescent Lights

Fluorescent lighting generally isn’t as popular for home growers. They are best suited to small plants, such as clones and seedlings. They generally don’t have the light intensity to support flowering plants, as their light doesn’t penetrate lower parts of a plant as much as LED or HID lights do. If you’re looking to start taking your first set of clones, or are starting off a seedling, fluorescent lights are cheap and can work well. 

Bonus Tip: Grow timers are essential to your plant having a steady light schedule. Cannabis plants need to be kept on a strict lighting routine to ensure they aren’t interrupted during their various stages of growth or you can experience issues like plants going to seed or poor flower production. 

Setting Up Ventilation in Your Cannabis Grow Tent

Providing your plants with fresh air is an important part of setting up your grow tent. This is accomplished by using fans and ducting. An inline fan brings fresh air into the grow tent, replenishing the CO2 levels, in addition to moderating temperature and humidity. Air movement from other fans in the tent is important to simulate wind, which produces stronger stems and prevents air from stagnating in the tent.

Inline Fan

In order to regulate the environment in the tent, there needs to be a regular exchange of air to ensure your tent has the correct humidity and temperature levels. An inline fan exhausts the air from your tent (often with a carbon filter attached to the end of the fan to mitigate odor) and helps regulate the air in your grow environment. This is a must if you plan to grow indoors in a tent.

Additional Fans Inside Tent

Whether you have oscillating fans or stationary fans, your goal as a grower is to ensure that there isn’t any stagnant air inside your tent. This is especially critical during flower as mold can develop above 60% humidity. While some strains are less prone to mold than others, keeping airflow in your tent is healthy for the plants as it mimics the wind the plant would receive outdoors. 

Carbon Filters

Carbon filters are a must if you’re concerned about your whole house smelling like cannabis. Carbon filters are attached to the tent’s inline fan and the activated carbon in the filters traps the smells, preventing them from leaving the grow tent. We’ve had a lot of success using carbon filters on our tents and highly recommend using them if smell is a concern. 

Ducting

Ducting provides a passage for air to travel through as the inline fan expels it from the tent. While an inline fan can be used without ducting, ducting and duct clamps are nice to have, as they allow you to set your inline fan up where you want it.

Climate Control Tools for Healthy Cannabis Plant Growth

As indoor growers, we are attempting to create the perfect environment for a cannabis plant to thrive and produce flower that we will enjoy consuming. Maintaining proper environmental ranges is critical and keeping a well maintained environment will allow you to produce the most enjoyable bud. Keeping optimal temperature levels helps maintain steady growth, and colder temperatures during flower can stress the plant, in a way we desire as growers, resulting in richer trichome development. 

Temperature Controller

Maintaining a temperature between 65-85F (65-80F during flower) allows your plants to grow steady, and absorb the maximum amount of energy it can through photosynthesis.  Environmental controllers, such as InkBird or AC Infinity Controller 69, allow you to set your ideal range of temperatures and humidity in your tent. These controllers have hygrometers and thermometers to measure these variables. Sometimes it is necessary to supplement heat to prevent your plant from being stunted by cold weather. When a grow environment is too hot, you get stressed plants, reduced photosynthesis, and terpene evaporation at varying temperatures. You may also supplement with air conditioning if needed. Cooler temperatures can stress the plant in a positive way, resulting in more production of trichomes, which holds all of the cannabinoids and terpenes (aka the flavor and effects of the strain). Even though cooler temperatures can be beneficial, anything more than a 10-15 degree drop in temperature between day and nighttime is enough to potentially stunt the growth of the plant. The environmental controller will help keep your tent within acceptable parameters since you can connect heating, air conditioning, humidifiers or dehumidifiers among other equipment and ventilation equipment to them.

Humidifiers

Cannabis plants tend to love humidity during the seed and clone stage and still respond well to high levels of humidity (70%) during the vegetative stage. Humidity should be lowered during flower, eventually tapering below 60% by the time the plants have finished stretching and started forming buds. A humidity monitor will tell you exactly where you’re at in your tent so you can use the humidifier accordingly. 

Bonus tip: Humidifiers should be cleaned regularly. Use  distilled or reverse-osmosis water to prevent hard water buildup in your humidifier (and on your plants). 

Dehumidifiers

Dehumidifiers become very important during the flower stage since you don’t want your humidity level above 60%. Dehumidifiers are loud, demand a high volume of energy, and emit a substantial amount of heat, so it may not be the best idea to add this inside your tent. I find it best to keep my lung room (the room containing the grow tent) at a lower humidity, so plants in flower don’t require a dehumidifier inside the tent. An ideal dehumidifier setup involves running a hose from the dehumidifier to a drain or reservoir that can be dumped at a later time. 

Tools to Upgrade Your Indoor Cannabis Grow Setup

While the items above are what I would consider essential grow tent items, there are several other items that will help make your grow setup as dialed in as possible. 

Support Bars

Support bars attach to the poles of your grow tent, and prevent the tent from being “sucked in” due to the negative pressure created when more air is expelled from the tent than is brought in. Support bars also allow you to retain the exact size your tent is supposed to be, since a grow space is minimized when the tent walls are pulled inward. This means more space for your plant to spread out!

Rope Ratchets

Rope ratchets typically come with accessories, such as lights, but it can be beneficial to own extra rope ratchets in the event you want to hang something else in your tent such as carbon filters, inline fans, or other accessories. 

Zip Ties

Zip ties are helpful for securing various items to support bars in your tent. They can secure an inline fan, scrog nets, or be used to manage cords. Even if you don’t use them for the reasons listed, you’ll likely find some use for these in your grow room. 

Scrog Nets

Scrog nets, or the screen of green, is a horizontal trellis/grid that is used to train plants. When growing cannabis, maximizing your space allows you to get the most out of your harvest. Filling as many squares in a scrog net as possible is a way to ensure you get a large, high quality harvest, with evenly lit flowers. Scrog nets can also be helpful at the end of a grow when hanging your plants to dry. Secure a scrog net to a higher portion of your tent and hang your branches from clothes hangers on the net. 

Conclusion

Grow tents allow growers to create a contained environment that is optimally suited for growing cannabis. Getting your tent setup and getting the environment dialed in, allows you to focus your time on other important tasks in the garden. Make sure your equipment can run and maintain a steady temperature and humidity, and if you can do that, there should be little adjustments from there on. Now that your tent’s set up, you’re ready to grow some amazing weed. Good luck and happy growing!