We all have to start somewhere. If you’re new to the cannabis-growing world, then you undoubtingly have a lot of questions. How can I make sure you grow healthy crops? What are good conditions for the plants? How can I bring your crops to flower as efficiently as possible? It all comes down to learning how to set up a grow tent – and an awesome one at that.
Finding the Right Space
Where you choose to grow your crop can make or break your cannabis garden. The cannabis plant, like any other plant, has specific requirements needed in order to survive and thrive.
Cannabis Growing Conditions
- Space: The minimum recommended square footage per cannabis plant is 4 ft2. This gives every plant enough room to stretch their leaves and grow into their full potential for harvest.
- Light: Cannabis plants need light for specific hours if you want them to flower, the exception being auto-flowering strains. Since the plants flower when days get shorter, you need to provide 14-16 hours of light when the plants are growing, and then reduce to 12 hours when you want them to flower.
- Temperature: Cannabis plants prefer temperatures between 70-80 degrees Fahrenheit for their entire lifespan. Keeping your cannabis plants towards the top of that range when they’re growing and towards the bottom when you want them to flower can help your yields.
- Ventilation: Cannabis plants grow better when there’s some air circulation in their environment. This helps prevent mold and keeps plant pests from choosing your plants as their new home.
- Humidity: You definitely have to watch your humidity levels when growing cannabis – typically about 40-50% humidity will keep your plants healthy and happy.
Some states have a better climate for growing cannabis outside, including California, Washington, and Oregon. However, even in the best outdoor climate, you can only harvest one crop a year, due to lighting and temperature requirements. If you set up an indoor grow tent, you can harvest multiple crops a year, while ensuring that conditions are stable and suitable for your favorite plants.
Deciding on a Growing Medium
Once you’ve chosen where you want to grow your plants, you’re ready to decide what you want to grow them in. While many people use soil as their growing medium for cannabis, there are other options available.
Hydroponic systems have existed for centuries. If you’ve ever seen a plant with roots growing in a vase full of water, that’s a super-basic hydroponic setup. Instead of using soil as the nutrient-delivery system, hydroponics house the plant in an inert “growth medium” and deliver all the nutrients through water. This gives you complete control over how much your plants get of what, and when. It also helps guarantee high-quality harvests in record times. It also saves space, because you can grow much larger plants in less square footage.
There are tons of hydroponic options. The simplest is the Deep Water Culture method, where plants are placed in containers which then are suspended in trays of water. The water is circulated with a simple pump, and an air stone or similar product oxygenates the water, so the plants never have to leave the water.
From there you can get a bit fancy. For example, in the Nutrient Film method plants are placed in angled tubes to allow water to flow past all of their roots easily. Then there’s the Ebb and Flow method, where water pumps fill and drain the tanks in which the plants are suspended. And lastly, you have the Drip method, where plants are watered through drip tubes instead of suspended in water.
All of these systems allow for more control over your growing conditions. However, they all come with significant startup costs. Meanwhile, soil is frequently cheap or free. You can compost to enrich your soil, you can use commercially-available fertilizers, and you can plant in containers as simple as a 5-gallon bucket. Soil is certainly more budget-friendly than hydroponics, thus it’s popularity.
However, soil does have some downsides. Depending on where you source your soil, you can bring pests into your grow tent set up without evening knowing it. You also can’t be sure of the nutrient levels present in your soil unless you buy it from a specific company that actually lists its levels. Also, it can be difficult to reuse soil without significant fertilization, because after a few harvests the soil’s nutrients will be used up.
Both hydroponics and soil are great options for growing cannabis indoors. It all comes down to your budget and the time that you’re willing to spend nurturing and maintaining your plants.
Set Up Grow Lighting
There are dozens of types of indoor grow lights on the market to suit every grower and every situation. Different lights have different intensities, require different setups, and definitely require different funds to purchase. Before you set up your grow tent, you’ll need to decide how large an area you’ll be covering so that you can choose your lighting accordingly.
Many lights list their “photosynthetic photon light density” (PPFD), or light intensity, at different distances from the light. You want your PPFD levels to be between 1500-2000 μmol/m2s for truly optimal growth. However, that can be hard to reach without really breaking the bank on electricity bills. Many growers report successful crops with PPFD levels above 500 μmol/m2s.
Another thing to take into consideration when setting up your grow tent is the total area you need lit. One grow light may have a stellar PPFD, but not cover enough space, while another can cover the whole space at a serviceable PPFD. The plants outside the light’s coverage area will still look lit, but they won’t be receiving enough light to reach their full growth potential.
There are PPFD testing units you can get if you’re curious about the specific PPFD readings at different distances, these can be expensive, however. If you buy your grow lights from a reputable company and follow their instructions for placement, you should be fine without one.
Finally, make sure that your grow lights are secure, however you mount them (note: be sure to following directions for the specific light so that you don’t burn your plants from placing it too close). The last thing you want is for your lighting rig to fall on your plants. Most grow lights are designed to be hung from the ceiling or from overhead racks. Take time to make sure that the rack or ceiling can hold the weight of the grow lights, or you’ll have a disaster just waiting to happen.
Types of Grow Lighting
Grow lights can be divided into several basic categories, with each of them having their own pros and cons.
LEDs are the most energy-efficient grow light option today. If you’re growing a lot of plants, LEDs are going to save you a lot on your energy bill. LEDs last about 50,000 hours, which is five times longer than HID lights and two and a half times longer than CFLs. They also have great light-intensity, so you can easily grow huge, healthy buds.
LEDs come in a variety of shapes, styles, and price points, but in general they’re the most expensive option, as they’re the newest (though it seems like they’ve been around for years) and most complex light on the market. However, due to their low energy-usage and shelf-life , they are more cost-effective in the long run. If you’re planning on growing for a long time, or have a big space you need to light, LEDs are definitely a great choice.
- Super-long lifespan
- Super energy-efficient
- Great light-intensity
- Less hot than most alternatives
- Directional light
There are two main kinds of high-intensity discharge (HID) grow lights: metal halide (MH), and high-pressure sodium (HPS). HPS lights are usually reddish and are great for helping plants flower, though they can be used for the whole growing period. MH grow lights tend towards blueish light, which means that helps plants build vegetation, though they’re not so great for the flowering stage. HIDs can be used one at a time or in concert.
The biggest issue with HID grow lights is that they use a lot of energy. Of the electricity they use, about three-quarters of that is turned into heat, so they’re a bit impractical and even dangerous in enclosed spaces. If you have a lot of room but not a ton of cash at the start, HID grow lights are a good choice.
- Less expensive than LEDs
- Great light intensity
- Good coverage
- Use lots of energy
- Create lots of heat
CFL stands for “Compact Fluorescent Light.” These are the curly lights often seen in light fixtures in most homes across the country. “Daylight” style CFL grow lights are great for spurring vegetation growth, due to the bluer tone of the light. Meanwhile, “warm white” lights have a reddish tint that helps plants flower.
While individual CFL grow light aren’t strong enough to grow a full crop unless they’re inches away from the plants, by using several in combination you can usually bring two to three plants to flower successfully. If you’re just beginning your cannabis-growing journey, CFL grow lights are a great introductory option.
- Easy to find
- Fit standard light fixtures
- Poor light intensity
- Not as energy-efficient as LEDs
Configuring Ventilation and Humidity
Once you’ve figured out the ideal lighting and grow medium for your cannabis plants, you’ll then need to figure out how they’ve breath. Ventilation is crucial to growing strong, healthy plants, so taking shortcuts can certainly hurt you come harvest time. Problems such as mold growth, stunted plants, or dead foliage can make your hard-earned equipment bucks so down the drain in a matter of weeks.
Plants use CO2 as a part of their energy-creation process. If your grow tent doesn’t have fresh air constantly coming in, it’ll run out of CO2 and your plants will die from too much oxygen. That’s right, oxygen is great for humans, but can be detrimental to plants. A lack of CO2 results in inefficient photosynthesis, which leads to stunted plants.
Another big reason why ventilation is important is temperature control. Even the simplest, most low-profile LED grow light generates some heat. If you’re using HID grow lights for your grow tent, then you’re generating a lot of heat. And if you’re not careful, you can easily cook your plants.
A solid ventilation system helps bring in cool air from outside the tent, while venting hot air back out. This keeps cannabis plants nice and comfortable in their preferred temperature range of 70-80 degrees Fahrenheit.
Airflow also helps keep your plants healthy. Having a breeze in your grow tent that can just slightly rustle the leaves of your plants helps keep your plants pest-free. Spider mites manage to get everywhere, no matter how sterile your set-up. However, they’re easily defeated by a light breeze, so your ventilation system can help keep them at bay. The airflow also keeps leaves dry, which helps to deter mildew, mold, and fungus growth.
Your grow tent’s humidity affects how prone to mold your cannabis plants are. Keeping the humidity level between 40-50% keeps your plants from losing water too quickly, while also preventing the kind of environment where gross things thrive (i.e. organisms that thrive on moisture). A solid ventilation system will help get rid of excess water vapor in the air.
It’s a good idea to purchase a dehumidifier when setting up your grow tent, in the event that you accidentally over-water your plants and need to lower the humidity levels.
Electricity Cost/Power Usage Expectations
Be prepared for ongoing costs after setting up your grow tent. Grow tents obviously use electricity every day in order to power their grow lights. And depending on your set up, you may also have fans, pumps, sensors, and a variety of other gadgets that live on the grid.
Luckily, it’s relatively easy to figure out the basic amount of electricity you can expect to use for your garden. Here’s how you calculate how much power usage for your grow tent:
- Measure the square footage of your grow tent – Width X Length.
- Check your preferred lights for their coverage, or how many square feet they cover with their stated PPFD levels.
- Divide your grow tent square footage by your preferred light’s coverage. This’ll tell you how many lights you’ll need for your tent. For example, if your tent is 16 ft2 and the light you intend to use covers 8 ft2, then you need two lights.
- If you use a HID light, check its wattage. For an LED, check its used wattage, not the wattage of HID with which it’s comparable – the wattage in the name is often misleading.
- Multiply that wattage by how many lights you need.
During the growing phase, you’ll use that many watts for 14-16 hours a day, and during the flowering phase, you’ll use it for 12 hours.
Other electrical elements should also list their wattage, so you should add those in as well. Remember, only your lights won’t run all day, so all your other equipment calculations should be for 24 hours.
The rule of thumb is that you end up using 50-75 watts per square foot of plant. (If you’re using LED grow lights, this can go down significantly.) This means that for an average grow tent that contains six plants in 24 ft2, you’re going to use 1200-1600 watts of power per hour when the lights are on. At an electricity cost of $0.12 per kilowatt (1000 watts), that’s going to run you at least $70 a month for two months. However, you’ll end up with a 6-plant harvest that’s worth bragging out.
Growing your own cannabis at home can be hugely rewarding. Take time planning the build of your grow tent before purchasing equipment, and always check the grow requirements for the specific strain of cannabis that you’re growing.
Knowing what you need upfront can save you tons of headaches once you start your setup and growing processes. Happy growing!