How to Optimize Your Environment in Indoor Grow Tents for Your Cannabis

Read our Ultimate Checklist for Growing Cannabis Indoors and wondering “What’s next?” Once you set up your tent and buy more equipment, indoor growers often wonder the best way to go about growing cannabis. Lucky for you, we have an article for that too. Your environmental conditions will have a dramatic effect on how well your plants develop. You can optimize temperature, humidity, grow light, and other factors to create the perfect conditions for your cannabis plant. This article will cover optimizing these four areas plus others with tips to make you feel like a pro grower.

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Growing in Indoor Tent Environments

What are the advantages of using an indoor grow tent for cannabis?

The main advantage of using an indoor grow tent for cannabis cultivators is the ease with which you can optimize your environment. Many models come with built-in lighting, fans, filters, and vents to make it easy for you to create a comfortable atmosphere for plant growth. The tents are also relatively small and easy to set up, making them a great choice for growers who have limited space. By having a defined closed space, you will be able to control various aspects of the environment better than if it was in a bigger space. Simply put, grow tents help you control and optimize:

  • Temperature
  • Humidity
  • Light
  • PH
  • Ventilation
  • VPD

What are some tips that will help me optimize temperature?

If you are using an air conditioning unit to cool your grow area, make sure the temperature is set no lower than 65 degrees Fahrenheit (18 degrees Celsius). If you are not using AC, aim to keep the temperature between 68 and 81 degrees Fahrenheit (18 and 27 degrees Celsius ). You may need a heating unit during colder months to maintain this temperature. The temperature of the room that the tent is in should also be taken into account when trying to regulate the temperature. For example, if the room your tent is in has an air conditioner in it, then it will be much easier to keep your temperatures down during the warm months.
With grow tents, you can also use fans (which we will talk about later) and open various flaps on your tent to help control temperature, humidity, and circulation. Please be mindful when it is lights out that open flaps can cause light leaks which can cause a plant to turn into a hermaphrodite.

What are some tips that will help me optimize humidity?

If you want to increase humidity, try using a humidifier. If you want to decrease humidity, you can use a dehumidifier. Many tents come with built-in humidity monitors to help you keep track of the levels in your tent. You can also use a hygrometer, which we highly recommend for any tent, to get an accurate reading.

As with temperature, the various flaps on your tent can help you optimize your humidity, just be cognizant not to leave them open when the lights turn out. You should also be conscious of the humidity in the room your tent is in to help optimize your grow environment.

How do I optimize my light for a tent grow?

The amount of light a cannabis plant needs depends on its stage of growth. During the vegetative stage, your plant will need between 18 and 24 hours of light per day. During the flowering stage, you will need to reduce the amount of light to 12 hours per day. Whether you have photoperiod or automatic seeds will also play a factor in your indoor light schedule. Cannabis growers will often measure their light coverage at different points in their tent using a meter, either a separate piece of equipment or even an app on your smartphone, that uses either daily light integral (DLI), lux, or photosynthetic photon flux density (PPFD) as a measurement for light intensity at canopy level.

Many growers use high-pressure sodium (HPS) or metal halide (MH) bulbs during the vegetative stage and then switch to LED lights for the flowering stage. When growing in a tent, it is best to use LED or fluorescent grow lamps rather than HPS/MH bulbs because they produce less heat while using less electricity. LEDs are quickly becoming the most popular option due to their comparative lack of heat and how cheap they are on the market now. Some even come with drivers, which means the motor that produces the light, that are detachable and you can place them outside the tent so as not to heat your tent unnecessarily from the heat it gives off while being turned on. With tents, you can easily install the lights and put them up high to keep them out of your plants’ way too. Some lights, especially LEDs, come with dimmers so you can also control the light’s strength during different stages of cannabis plant growth.

How do I optimize my pH for my indoor grow environment?

PH is a measure of how acidic or alkaline soil is. Cannabis prefers to grow in slightly acidic, neutral, or alkaline soils with a pH between the ranges of about six and seven in soil. You will also need to take pH measurements if you are growing using hydroponics and coco coir too. For soilless grows, so using hydroponics or coco coir, the optimal pH range is 5.8-6.0 while the general range for soil is between 6.0-7.0 with 6.5 being optimal. You can purchase an inexpensive tester for this online that will help you keep track of your levels throughout the growth process. However, we recommend that you buy an Apera, Bluelabs, Hannah Instruments, or any other reputable pH pen manufacturer due to the cheap Amazon pens continually breaking. These brands will cost more but should last far longer while giving more accurate readings too.

How do I optimize my ventilation for my indoor grow environment?

One of the most important factors in optimizing your growing environment is to make sure you have proper airflow. It can be difficult if you are using a tent, which has flaps that cannot remain open when the lights turn off. However, there are some advantages to tents; they often come equipped with duct ports to attach intake and outtake fans too. These additions help and we will go in-depth on how to equip your tent with the right fans and ventilation equipment to optimize your grow environment.

Oscillating fans
Many growers use oscillating fans in their tent grow room to create airflow. The fan should be placed on one of the supporting bars of your tent and directed so that it circulates the air throughout the tent. This will help to prevent hot and cold spots, which can stress your plants, and will also help to keep the humidity levels more consistent. Two oscillating fans are optimal and one should be placed above the canopy while the other should be placed below or directly on your bud sites so the colas do not develop any fungus or mildew.

Exhaust fans or intake/outtake fans
Intake fans help by bringing fresh air into the grow area while exhaust fans help remove hot, stale air. It is important to have one of each type of fan in order for your grow environment to be successful. The intake fan should be placed on the outside of your tent so that it brings in cool, fresh air, and the exhaust fan should be placed at the top of your tent and should have a ducting system that leads outside the grow area. The air needs to be pulled out of the tent so that it can circulate fresh air through your grow area. The outtake fan is especially important if you are using a light that emits a lot of heat, as it can produce a considerable amount of heat and must have proper airflow to keep them cool enough for optimal use. These fans also help if you are using a carbon filter, as it will help to remove the smell of cannabis from your grow area before being circulated out of the tent.

What is VPD and how do I optimize it?

VPD stands for vapor pressure deficit and is a critical parameter in optimizing your growing environment. It measures the difference between how much water vapor pressure it takes to evaporate water from plant leaves, which is called transpiration, and how much water vapor pressure there actually is in the air around them. This number varies greatly depending on temperature and humidity levels. By optimizing your VPD you can help to optimize the growth of your cannabis plants by providing them with an environment that is close to their natural environment. You can find a calculator or charts online to help you determine what the VPD should be for your indoor grow area at any given time and using these tools is a great way to know the optimum humidity and temperatures at each stage of growth for indoor cultivators.

Smart Plugs & Power strips

What are smart plugs and smart power strips and how can they help my indoor cannabis grow?

A smart plug or power strip can act as and environmental control system and is a great tool for optimizing your indoor grow environment as it can help with many different parts of the process, especially temperature and humidity. Many have the option of setting parameters for your grow and once the environment in your grow tent is outside those parameters the smart plugs or power strips will then turn on a device to help maintain the optimal ranges. For example, if you have a smart power strip that you set the parameters for humidity during late flower in the range of 40% relative humidity and 55% relative humidity, the strip can turn on a humidifier if it is ever under 40% in your tent and turn it off if the humidity is over 55%. This can make it very easy to keep your tent within the optimum ranges. Your lights, although they can be switched on and off manually, will most likely also be connected to a smart plug or power strip. This will enable you to set a schedule for your lights whether you are home or not. Many of these devices offer the ability to at least monitor the environment in your tent from your smartphone and some even offer the ability to control it although prices can vary for different options.

Soil and Grow Mediums

What Soil Medium Should I Use?

There is a variety of different soil mediums that work well for growing cannabis, depending on your preferences and budget. The three most popular options include soil, coco coir, and hydroponic systems and there are experienced growers using each one. We will break down those three below.


Soil is a very popular medium for growing cannabis and the most cost-effective, but it does require proper nutrients added to balance out the pH levels of your plant’s root zone. If you use soil as a grow medium in your tent, ensure that it is 100% organic with no harmful chemicals or pesticides before adding any nutrients to avoid contaminating your plants. In a soil grow, nutrients can be added to the soil directly or there are liquid nutrient lines that you mix into your water when feeding. There are also different types of soil grows, such as no-till, living soil, and numerous other methods. Which one you choose will depend on how you want to grow your plants and the research you put into the various growing methods.

Coco Coir

Coco coir is made from the husks of coconuts and is often considered an “ideal” growing medium because it has a near-neutral pH, high water retention, and good air porosity for growing cannabis. It also typically has a higher EC (electrical conductivity) than soil due to the high concentration of salts that are naturally present in coconuts, which can be an advantage or disadvantage depending on your point of view. This could make it favorable if you’re optimizing pH since plants will generally uptake more nutrients at higher EC levels, but if you are optimizing your nutrients for a lower EC level then it can be unfavorable. There are not many nutrients in coco coir that are formulated for cannabis, therefore you will have to use a special nutrient line that has been optimized for coco coir or add additional nutrients from other products.

Hydroponic Systems

A hydroponic system is one in which the plant’s roots are not actually in soil, but are instead suspended in a nutrient-rich water solution. This can be done in many different ways such as using a grow tray with individual pots that each hold a plant or using a deep water culture (DWC) system in which the plants’ roots are submerged directly into the nutrient solution. This method is often considered to be the most efficient way to grow cannabis as it allows you to closely monitor and adjust the levels of nutrients and pH in the root zone, but it can also be more expensive than other methods as you will need to continually add nutrients and will have to set up a system that contains a reservoir for your water and tubing or pipes to bring the water to each plant. It should be noted that this system can be automated too but that will typically make it even more expensive.

Once I have set up my indoor grow environment what should I do next?

The first thing you should do before adding any plants to your indoor grow environment optimizes the temperature and humidity levels. This can be done by ensuring that there are fans for air circulation in your tent, as well as an exhaust system with a carbon filter to prevent smells from escaping. If using a hydroponic system then we recommend optimizing both your temperature and humidity levels to ensure maximum yields.

Next, you should optimize the level of lighting that will be used in order to determine how many watts/grow lights you need for each plant. You should also take into account the size of your tent when choosing your lighting. If you have a bigger tent, a bigger, stronger, light will be necessary to ensure the light is strong enough in all parts of your tent to maximize yields.

Lastly, always ensure your pH levels are in the correct range for cannabis plants and use a pH meter to test your water and nutrient solution. The ideal pH range will vary depending on your medium so ensure it is always in the correct range. When using coco coir or soil, always pH the runoff after watering to ensure the medium is not changing it drastically.

The main thing to remember is that there is no one perfect way to grow cannabis and optimizing your indoor grow environment will require careful planning.


If you plan to grow indoors, optimizing your environment can help you take your yields to the next level. Whether it is temperature, humidity, or lights, making small tweaks can have a large impact on the quality and size of your final product. Your fans will help with circulation and keeping your temperature and humidity in optimal ranges while a decent pH will ensure that you are feeding the right pH water for your plants to uptake nutrients. VPD is the last piece of the puzzle when growing as it will tell you the optimum ranges for both your temperature and humidity for your plants to thrive. Finally, choosing the right medium can have a large influence on the quality of yields for cannabis and all three have their pros and cons. Whether it is soil, coco coir, or hydroponics, will be determined by you, your price range, what’s available, and your preference for the grow.

Thank you for reading our article, should you have any further questions please read our other articles on pH, soil, coco coir, hydroponics, and VPD. Also be sure to check out our resources for troubleshooting your cannabis grow

I don’t always grow, but when I dor, I grow with bionics.