How To Build The Ultimate Indoor Grow Room Part 1


Tyler Markwart

Medical cannabis activist, farmer, hash maker, syndicated journalist, and consultant with over 25 years experience in the medical, legacy, and recreational markets

With the recreational cannabis market flooded with lower quality products and burdened with excessive taxation rates, there is no better time than now to start growing your own cannabis at home. But if you’ve never grown before where do you even begin? Let’s start out with a few questions that will help you decide which pathway is best for you. 

5 questions to address before starting your indoor grow:

1. How much dried material am I looking to produce? 

2. How much space do I have to work with?

3. How much money do I have to invest up front and over time?

4. How much electrical power do I have access to? 

5. How much time do I have to devote to gardening each day? 

Let's go over each of these questions and see if home growing is a good fit for you. 

How much dried material am I looking to produce?  

Are you looking to produce enough cannabis so you don’t have to buy from the retail stores or from the legacy market? Or are you just looking to supplement your stash and roll up fatties when you’re at your friend's BBQ this summer?

If you are a daily smoker, keeping track of your daily, weekly, and monthly consumption rates will help calculate how many plants you need to grow. Once you figure out how much you are consuming then you can work your way backwards and you can figure out how many plants you need to grow each year to provide for your needs.  For instance if you smoke 1 gram a day, you are going to be smoking less than half a kilo (less than 1 pound) of dried cannabis flower each year. 




How much space do I have to work with? 

This question is one of the bigger limiting factors when it comes to indoor growing. Most people do not have several thousand square feet to set up their plants and equipment, so planning out this portion of the grow can be a little bit tricky.

Cannabis has essentially three life stages when growing from seed. There is the seedling stage of growth, which starts when the seed (cannabis actually produces achenes and not seeds but it’s common to call them seeds) germinates and goes until the plant begins to produce branches and leaves. 

The next stage is called the vegetative stage of growth. This is where the plants begin to grow more branches and leaves, and depending on the plants’ genetics and the environmental factors, they can grow rapidly or slowly in this stage.  

The third stage of the plant's life is the flowering stage. This is when the plant begins to produce flowers in hopes of being pollinated so that it can produce offspring. Fortunately (and unfortunately),  most cannabis plants are photosensitive. This means that the plant requires a change in the amount of darkness that the plant observes in order to go from the vegetative stage of growth to flowering stage of growth.  


The amount of darkness that the plant receives causes a hormonal shift in the plant that signals it's time to start producing flowers.  Outdoors this usually occurs after the longest day of the year, when the days start getting shorter and the nights start getting longer.  When you grow indoors, you get to control these environmental aspects and you can dictate how big the plant can get and when you want them to flower.  

So why is this all important to the question of how much space do I need? Well, if you don’t have reliable access to clean clones (cannabis plant cuttings with established roots) then you are going to have to grow from seed (achenes). If you want to be able to have a harvest every month or every two months growing from seed, then you need to be able to grow all three stages of the plant's life in different growing areas, under different lighting intensities and time schedules. 

We’ll walk through an example of how all this ties together at the end of this article, so just be patient and try not to get too discouraged with all this new information.  

How much money do I have to invest initially and over time? 

Most of us aren’t wealthy and we are living on a tight budget so dumping thousands of dollars into a grow isn’t in the books right now. The basic items to get growing are going to be a grow light, containers to grow the plants in, growing medium, and seeds/clones. This is the bare minimum to get plants to produce a harvest. 

This can be set up in a closet, in a spare bedroom, garage or anywhere a light can plug into an outlet with a sealed area where you can keep the light from entering and escaping.  From here you really have no limitations on what you can do. 


Most home growers opt to use grow tents, but some who want to grow larger amounts will build out an entire spare bedroom, basement or garage. If you are looking to grow high quality cannabis then you need to be able to control your environmental factors. Because just like people, cannabis has a preferred temperature range that it thrives in.  

So having technology in your room like HID or LED lights, humidifiers, dehumidifiers, fans for air circulation, carbon filters to combat smell, UV lights for sterilization, raised rolling grow tables, etc…all of these items can make the growing process easier and create a higher quality product, but they also require an initial capital investment as well as a continued expense through their electrical usage and maintenance. 

Planning out how much power consumption and money you need to invest into growing equipment and their power usage over time is something you’re going to want to plant ahead for.  

I have seen grows that have thrown millions of dollars at them and they are technologically superior to anything else, and I’ve seen small home closet grows that have had very little investment, both of these have and can produce high quality cannabis, and both can produce low quality as well. Attention to detail is the defining factor in both situations.  

 How much power do I have access to? 

Like the other questions we’ve jumped into, this one also can create some major bottlenecks, as well as safety issues if you don’t pay attention. The last thing you want to do is burn your house down because you overloaded one of the circuits in your house.  This section comes with a substantial warning! ELECTRICITY CAN KILL YOU! 

If you are nervous or don’t understand how power works, please, please, please inquire with someone who is licensed and can help you put together your grow properly.  I am not a licensed electrician but I am a certified mechanic who has been trained in electrical circuits and how power works. Though they are not the same as far as voltage levels go, they share many similarities. With that being said, the most important thing to acknowledge is how much power you have access to, and how large are your circuit breakers.  

Most contemporary homes are built with 20amp circuit breakers. This means that it’s likely that most of the electrical sockets in one of your bedrooms can handle up to 20 amps of power before the breaker trips. Here is an important aspect to remember, when electrical components such as grow lights, dehumidifiers, fans and other equipment turn on, they usually draw more power than they advertise on their label.  


The number on the label generally refers to the amount of power the unit draws when it is up and running in a stable environment.  So if you calculate all your grow equipment to be 19 amps and it’s all running on one circuit, it’s more than likely that the circuit will trip and none of the equipment will turn on. This can cause issues with vegetative plants because they will go into the flower stage because they are getting too much time in the dark. 

If you are going to incorporate extension cords into your grow, make sure you match the wire gauge which is referred to as “AWG” to its proper rating for the equipment that you are using. 

How much time do you have to devote to gardening? 

This question really helps define what the overall product quality is going to be.  Spending time in your grow every day helps you build a strong bond with your plants as they grow. 

Attention to detail is one of the greatest skill sets a gardener can have.  Knowing what pests you are going to be facing, when to water, when to apply nutrition in the soil and as a foliar application, etc…all take time to learn.  Do as much research and reading as you can before you begin to invest into home growing because many of us have made mistakes that you can simply avoid by reading grow forums, interacting with other growers on social media, and reading cannabis and other agriculture books and magazines.  

Most people don’t have several hours every day to contribute to their garden, and many people enjoy going on vacations or short weekend holidays.  If this is the kind of lifestyle you live and you want to grow cannabis at home indoors, then you are going to have to invest in technologies that automate your water, nutrition and other environmental conditions. You can also have a family member or friend help you out and water your plants while you’re away, but that person should really be trustworthy and have a green thumb if they are going to be managing your garden while you are away.  

In short, creating a schedule of your day and figuring out when you can fit in gardening work in between your job, kids, going to the gym, etc. is going to help you figure out if growing at home is going to work out for you. 

Example of a grow setup for one person who consumes 1 gram/day of cannabis:

  • 1 x grow tent/room/area for vegetative growth and starting seedlings or rooting clones
  • 1 x grow tent/room/area for flowering growth
  • 1 x grow tent/room/area for drying
  • 1 x dehumidifier for flowering tent
  • 1 x dehumidifier for drying (this is depending on your location i.e. desert and other dry locations)
  • 1 x humidifier for vegetative growth
  • 1 x light for vegetative growth
  • 1 x light for flowering growth 
  • 1 x exhaust fan for flowering tent/room
  • 1 x fan to circulate air inside each of your grow tents
  • 1 x carbon filter
  • Containers/beds for flowering stage (depends on the size of your tent) 
  • Containers for vegetative stage (depends on the size of your tent) 
  • 1 x Clone/seedling tray and dome for clones and seedlings
  • 1 x Watering can
  • 1 x pH/PPM/EC meter (optional) 
  • 1 x 30mL (1 ounce) Measuring cup
  • 1 x 500mL measuring cup 
  • 1 x 1000mL measuring cup
  • 1 x food grade 5 gallon bucket 
  • 1 x plastic or bamboo stir stick 

Now you don’t technically need to have three grow tents or areas for your set up, this is especially true if you have access to clones and teens (teens are larger plants that are also known as RTF’s, or Ready To Flower). Many states in the US have laws that allow cannabis retailers and/or farms to distribute plants that are larger and ready to flower for customers who don't have or want to keep mom plants. So check your local laws to see what your local access to cannabis plants is. 

A mother or mom plant is a female plant that has desirable characteristics that you want to grow each cycle.  It is possible to keep cannabis in its vegetative stage by keeping the lights off for less than 10 hours a day.  


Now there is also an important note to be made about the photoperiod (light cycles) of the cannabis plant. Most cannabis plants are photoperiodic as I discussed earlier in this article, meaning that the amount of continual darkness that the plant observes dictates when it will start flowering.  But there are also plants that will begin to flower if the dark part of the day is longer than 6 hours.  

On top of that there is another subset of cannabis plants known as ruderalis. These cannabis plants don’t react to the light cycle changes and begin to flower when they reach a certain age. So there are lots of options for people to access a variety of different plants that perform under different situations.  The real goal to success is learning what your plant likes and doesn’t like.  The better you get to know your plant, which happens after growing it several times, the better your final product will be.

What size tent should you purchase? 

There are a variety of different sized grow tents available on the market. Let's say you consume about 1 gram of flower a day.  In this instance you can either grow one larger batch of plants and harvest them all at once and be set for the year, which would allow you to travel and not be constantly tied to the responsibilities of your grow. Or you could grow several smaller harvests throughout the year so you can have more opportunities to learn and more variety in your plant selection.

Just like in other agricultural crops, cannabis yields vary due to environmental conditions and the plant's genetic potential.  Some cultivars of cannabis are low yielding but produce very potent and resinous flowers. While other cultivars yield substantially larger amounts but may be less potent and have more leaves.  Do some research on the plants that you are going to grow. 

Most breeders and seed banks will display how much their seeds can potentially yield and how quickly they will finish flowering.  If you are new to cannabis gardening then perhaps classic equatorial lines like hazes that take 12-24 weeks to finish and are very sensitive to environmental stimuli are not the best choice to start out with.  If you are new, do some research to find plants that are easier to grow, less susceptible to pests and disease and don’t require a lot of care to produce a really good final product.  

Plants like Blue Dream and Gorilla Glue are hearty and can still produce good results under tough conditions.  




When choosing a grow tent or growing space, it's important to remember that the plant can double or even triple its height in weeks 1-3 of the flowering stage.  This is really important because it will help you dictate what size tent you need and how tall to grow your plants before you flip the lights from one light cycle to the other.  Most people generally opt for a 4’x4’ sized tent which is generally about 7 feet tall.  

Calculating the height of your growing container, plus the height of the plant, plus the size of your grow light and other equipment that is hanging inside the tent will all dictate which size tent you need to purchase for your situation. If you aren’t using a tent then you need to measure your usable ceiling height and adjust your growing style according to the parameters that you have available to you.  

Grow tents like all products come in a variety of grades. You have low quality, medium quality and high quality tents.  It's extremely important to remember that you often get what you pay for. The cheaper quality tents have poor quality control and often will have holes in them that leak light, or they can often be poorly constructed using cheap materials.  Generally more expensive grow tents hold together better over time because they are made with better materials.  This is all dependent on what can fit in your budget, but remember you may end up having to buy two tents compared to one because of the quality of the zippers or the flaps degrade over time.  

Like I mentioned before, most growers will opt for a 4x4 tent to flower in.  This will generally hold four 5 gallon containers or one large bed which can hold 4 large plants or 9-12 small plants if grown in the sea of green style method. 


Growing cannabis can be a wonderful experience and it also can be frustrating and expensive if you don’t plan and aren’t able to adapt when needed.  Take the time and do research on everything you can before you invest time and money into this project.  In the second part of this article I will go more in depth on how to select container sizes, which mediums to use, mulching, choosing a nutrient and pesticide program as well as drying, curing and storage of the flowers after harvest. 

Thoughts? Let us know by joining our secret Facebook group. Hang out with a community of like-minded solventless heads like yourself. Ask our head extractor questions, share your latest press and learn from hobbyists and experts in the industry.


Should I grow my own cannabis indoors?
Whether or not you should grow cannabis at home depends on several factors, including the amount of cannabis you need, the amount of space you have, how much money you have to invest up front and over time, how much electrical power do you have access to, how much time do you have to devote to gardening each day.

What do I need to grow my own cannabis indoors at home?
At the bare minimum you need an enclosed space with exhaust and ventilation, containers and a growing medium to hold the plants, a grow light with a timer, and nutrients to feed the plants. 

How much space do I need to grow cannabis indoors?
You can flower a cannabis plant in as little as 2x2 square feet of space. Many home growers opt for a 4x4 foot grow tent. 

How long does it take to harvest cannabis indoors?
The time to harvest depends on whether you're starting from seeds or clones. Once the plants begin to flower, it takes around 60-80 days until they're ready to harvest. All in all, expect 3-4 months for a grow to finish its full cycle. 

Can anyone grow cannabis at home?
The supplies you need to grow cannabis at home are readily available and compatible with most budgets. With willingness to learn, persistence, and attention to detail, anyone can grow and harvest cannabis flowers. The legality of cannabis in your location is a different question. 


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