How To Build Your Own Indoor Grow Room

How To Build Your Own Indoor Grow Room


Growing cannabis indoors is more efficient when you have a perfectly set up grow room. The grow room is where the entire life cycle of your cannabis plants take place: from germination and early growing, to vegetation and flowering.

Your success in growing cannabis indoors is largely dependent on the grow room. While there are many grow room models in the market, you can easily make your own provided that you have the space needed. The space and size of grow room can be determined based on what’s available, how much cannabis you want to grow, and the strains you want to grow. If you are growing for medicinal purposes, for yourself or for another person, patients typically consume around 1 to 2 grams of pot a day. For recreational use, that will depend on how much and how often you smoke.


Deciding where you’ll install a grow room is important since privacy should be your top priority. It’s also important that the location affords you major control because if you can’t control the environment there’s no use growing weed indoors. Attics and cellars are always a good choice, if you have one. But that doesn’t mean you can’t grow weed indoors if all you have is an apartment. A safe estimate is around 4 plants in each square meter.

For small spaces, cupboards and a wall cabinet make excellent indoor grow room locations.  Cupboards are good enough to produce adequate cannabis for medical consumption while being easy enough to cover up. Just make sure that the cupboard or wall cabinet you choose also enables you to have enough space to to work and move around. 

Grow tents are smart and efficient; they are made waterproof, lightproof, and airtight which in itself already drastically solves numerous problems that growers face. These rectangular tents can hold your hydroponics equipment or soil, while some are fitted with drain or drip systems. The major advantage with using a grow tent is that you can have complete control on the growing environment including light, humidity, temperature, and location. Grow tents are also usually portable since these are designed with the hobby grower in mind.

A full-sized grow room is always ideal, if you have the space. Cannabis plants grow well in full-sized grow tents because they offer enough space for fans, and can also be ventilated with outside air through a window, for example. If you have a cellar, this is a great place to create an indoor grow room because it’s naturally cool underground and you’ll need less fans than using a full-sized grow room above ground.

Building Your Indoor Grow Room

Now that you have chosen a location for your grow room, here are the things you’ll need to take into consideration and plan for:



Your grow room should be completely light proof because cannabis plants require 12 hours of uninterrupted darkness to mimic night indoors, and it will also need 12 hours of light. If the 12 hour darkness is disrupted, this can ruin your harvest entirely in some cases or give you a smaller yield. If light creeps into the space, you can use lightproof tape to seal it in.

Additionally, you should also invest time in doing research on the kind of lighting you’ll use in the grow room. The most popular kinds of light that growers use include LED, high-pressure sodium (HPS), or fluorescent lights. Keep in mind that fluorescent and HPS lights get extremely hot, which means that using these options will require you to pay closer attention to temperature or even add fans if the temperatures rise. You’ll also need to carefully install lights, and make sure that there is space for airflow above lights while giving plants enough space. When the cannabis plants grow, the lights will also need to be adjusted to accommodate upward growth. For this reason, adjustable chains are best when hanging lights. Ideally, give lights around a foot of space from the grow room ceiling.


The Smell

Indoor grow rooms should be air tight because once your plants start to bloom, it will also start to emit a strong, fragrant odor. While you may love the smell of pot, your neighbors (and landlord) may have an issue so keep any problems at bay by ensuring that your grow room is air tight. Unless you live in total isolation, you’ll have to work on containing the smell of your grow room. Filtration systems are preferred by growers because of its efficiency in keeping the smell in. Additionally, make sure that there are no holes or cracks at all in the grow room, because the smell of cannabis may pass through these holes.



The ideal grow room should have consistent climate. Ventilators should be used to ensure air circulation, which also supports the growth of strong and healthy crops. If you have the money, you may want to look into using a thermostat which can be connected to an exhaust ventilator so that you can control temperatures with ease. Other options include a hygrostat or thermo-hygrostat. A dimmer switch also lets you control how fast the ventilator operates.

Depending on where you live, humidity and temperature will vary. If you’re growing in a climate similar to that of Arizona, you may face challenges with keeping your grow room humid enough. On the other hand, if your climate is like that of the Pacific Northwest, your challenge will be keeping humidity at bay.


Humidifiers are needed to regulate air moisture. Generally, humidifiers aren’t expensive; this equipment will save you time, energy, and headaches. Many humidifiers in the market are already built in with a hygrostat. Your cannabis plants will thrive in humid air, which will also shorten the time it spends during the growing phase.

Soil vs. Hydroponic Grow

Before you start a grow room, know what kind of system you want to grow your plants in. Soil and hydroponic grows each require a different set up and work with, and they each have their own equipment. Hydroponic systems are recommended for growers who have a small grow room since they generally require less space.

Waterproof Flooring

It’s expected that water from the pots will spill on the floor. Spraying your floor with water also helps increase humidity. For this reason, use a waterproof floor.

Reflective Material

Reflective bubble insulation or mirrors help maximize space and light in the grow room. Panda Paper and similar materials enable light to bounce back to your cannabis plants. Reflective walls also help ensure that any light in the grow room is concentrated on the plant instead of being wasted when absorbed by other materials in your grow room.

Collection Rack and Screens

If you are growing your plants in soil or rock wool, it’s recommended to use a collection rack placed at the bottom of your grow room. Collection racks are pretty simple; you can even create your own using short wires, as long as the plants can ‘sit’ on them. The purpose of a collection rack is to ensure that the plants are kept above the ground which benefits them in terms of air flow. Additionally, collection racks also ensure that the grow room is neat and tidy since any debris falls directly on the floor, allowing you to easily spot them and clean it up while reducing the risk of contamination and mildew.

Plant Setup

Once everything is in place, it’s time to add your plants either in your hydroponic system or placing them in soil-filled pots. If you are using soil, the pots should be at least 3 inches apart although this should significantly be more if you are growing large plants.


Here’s a useful list to get you started with grow room equipment:

  • Lights/lamp
  • Reflector
  • Ballast
  • Time switch
  • Air extractor
  • Carbon filter
  • Air intake
  • Controller with thermostat
  • Rotating fan
  • Thermometer
  • Hygrometer
  • Water tank
  • EC meter
  • pH meter
  • Watering can

Also keep in mind that each grow room is different. You’ll need to check the needs of your specific grow room, then set up a Co2 system based on your data. The more cannabis plants you have, the more Co2 you’ll need.

Cleaning Your Grow Room

Cannabis grow rooms should always be clean and well-maintained. Without routine cleaning, your grow room may spawn mold, fungus, and other disease that will plague cannabis plants and hinder their growth – or even cause the harvest to be a complete failure. A warm and humid environment is the best place for disease to grow and spread quickly, so it’s important that you nip these problems in the bud.

It’s always recommended to disinfect your grow room before and after each growing cycle. Use cleaning agents to wipe the entire space clean so that bacteria and other parasites don’t stand a chance when you have a new crop. Cleaning also requires getting rid of waste from plants, such as fallen leaves. If you encounter fungus or mold, you’ll have to let go of the entire crop.







High & Marijuana Blog | Cannabis

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