Easy Guide for Beginners to Grow Cannabis Indoors

Posted on Jun 20 , 2020


grow cannabis with COB LED grow in tent

Are you interested in growing your own cannabis plant. Indoor cannabis cultivation poses a unique set of challenges for amateurs, our easy-to-understand grow cannabis indoors guide will help you even the first time grower get started.

Benefitswhy grow cannabis indoors

  • High-quality marijuana: Indoor cultivation of marijuana, you can control all aspects of the environment and the items placed in the plant, so planting indoors allows you to dial into the setting to grow some original weeds.

  • Adaptability: Can you grow weeds anywhere and live in an apartment or small house? Even people with no backyard or too much extra space.

  • Harvest more: Harvest more cannabis every year. Unlike outdoor cultivation, indoor cultivation is not restricted by sunlight and seasons. You can grow cannabis anytime, anywhere, or even through the entire winter.

Step 1: Find a cannabis planting room or space


The first step to grow cannabis indoors is to find a planting space, which can be a closet, tent, cabinet, spare room, or corner in an unfinished basement.

When designing a space, you need to consider not only the space required by the plant, but also lighting, pipes, fans, and other equipment. You must also leave enough space to work. At the beginning of flowering, the size of the cannabis plant can be doubled, so make sure you have enough headroom!

If your growing room is a cabinet, tent or closet, you can simply open it and remove the plant to work on it; otherwise, you need to make sure you have some elbow space.

Pay attention to keeping the space clean, opaque, ventilated, and temperature and humidity suitable for plant growth.

Step 2: Choose the right cannabis grow light

Cultivating light indoors is the most important factor, so choosing a good, affordable grow light is very important.

Here is a brief description of the plant grow light suitable for indoor cannabis cultivation.

HID plant grow light

HID (High Intensity Discharge) lights are the industry standard and are widely used for their combination of output, efficiency, and value. They cost more than incandescent or fluorescent lights, but they produce much more light per unit of electricity. On the contrary, they are not as efficient as LED lighting, but their cost is only one-tenth that of similar products.

The two main types of HID lights used for growth are:

  • Metal halide (MH), the light emitted is blue and white, usually used during vegetative growth.

  • High-pressure sodium (HPS), which emits light more at the orange-red end of the spectrum, and is used during flowering.

In addition to the bulbs, the HID lighting setup also requires a ballast and a hood/reflector for each light. Some ballasts are designed for MH or HPS lights, and many newer designs will operate simultaneously.

HID lights generate a lot of heat. If the weather in the area where you live is relatively cold, you can choose HID grow lights.

Fluorescent light

Fluorescent light fixtures are very popular among small hobby growers:

  • Simple installation, low purchase and operation costs

  • Low heat generation, no cooling system required

The main disadvantage is the low efficiency of fluorescent lights. For every watt of electrical energy used, the amount of light produced is reduced by about 20-30%.

LED grow light

The main disadvantage of LED grow lights is their cost: the cost of well-designed lights may be 10 times that of similar HID devices. The advantage of this is that the LED has a longer lifespan, uses less electricity, generates less heat, and the best design can produce a more complete spectrum, which can improve yield and quality. Here we recommend you a cannabis grow light – 600W COB LED Grow light.

Best Marijuana Grow Light 2020

Step 3: Grow Cannabis Indoors with air

Plants need fresh air to grow, and carbon dioxide (CO2) is essential for photosynthesis. This means that you will need a steady flow of air through your growth chamber. This can be easily achieved by placing an exhaust fan near the top of the room to remove hotter air and filtering the air inlet on the other side near the ground.

You need to ensure that the temperature of the plant is within a comfortable range, that is, the temperature is between 70-85 F when the light is turned on, and 58-70 F when the light is turned off.

Keeping the breeze constant in the growing room is a good idea, because it can strengthen the stems of the plants and create a less hospitable environment for mold and flying insects. Wall-mounted circulation fans can do this well-do not point them directly at your plants, as this may cause burns.

Step 4: Choose climate control and monitor

After selecting the lighting and climate control equipment, you will need to perform its functions automatically. Although there are complex (expensive) equipment available to control lights, temperature, humidity and carbon dioxide levels, beginners will usually need a simple 24-hour light timer and an adjustable thermostat switch (for exhaust fans).

When you grow cannabis indoors, the timing of the light-dark cycle is very important. Normally, when plants are in vegetative growth, you will turn on the lights for 18 hours every 24 hours, and then switch to 12 hours for each 24 hours when you want them to bloom. You need to turn on and off the lights at the same time every day, otherwise it may cause stress to the plants, so you must use a timer. You can also use a timer for the exhaust fan, but spending a few more dollars on the thermostat is a better option.

With the most basic model, all you need to do is set the thermostat on the device to the highest temperature required for your space, and then insert the exhaust fan into it. After the temperature rises to the level you set, it will turn on the fan until the temperature drops a few degrees below the set threshold. This saves energy and maintains a stable temperature.

Since you may not spend most of your time in the growing space, the combination of hygrometer/thermostat and high/low memory function can be very convenient to understand the condition of the room. These small, inexpensive devices can display not only the current temperature and humidity levels, but also the highest and lowest readings for a period of time since the last inspection.

Step 5: Determine the growth medium for grow cannabis indoors

Growing indoors means you can choose a variety of different media. Whether it is an old-fashioned old flower pot filled with soil or a rock wool board in a hydroponic tray, each media has its advantages and disadvantages.

Here, we will study the two most popular methods and the media they use.


The soil is the most traditional medium for you grow cannabis indoors and the most tolerant, so it is the ideal choice for the first time growing cannabis. As long as there is no artificially extended fertilizer (such as Miracle Gro), any high-quality potting soil can be used. This fertilizer is not suitable for growing high-quality cannabis.

For beginners, a very good choice is organic fertilizer soil (often called “super soil”), if used correctly, cannabis plants can be grown from beginning to end without adding any nutrients. You can make your own by mixing worm castings, bat bird droppings and other components with good soil and leaving it for a few weeks, or you can pre-purchase from several different suppliers.

As with all organic cultivation, this method relies on healthy mycorrhizal and soil bacterial populations to promote the conversion of organic matter into usable nutrients for plants. Alternatively, you can use a conventional soil mixture and then add liquid nutrients to the plants after the soil has dried up.

Soilless (also known as hydroponics)

Indoor growers are increasingly turning to soilless hydroponic medium for you grow cannabis plants. This method requires feeding concentrated mineral salt nutrient solutions, which are directly absorbed by the roots through the infiltration process.

Techniques that speed up nutrient absorption lead to faster growth and higher yields, but because plants respond faster to excess or insufficient feed and are more vulnerable to nutrient lock-in and burning, higher accuracy is also required.

The different materials used include rock wool, ver stone, expanded clay pebbles, perlite and coconut fiber, to name a few. Commercial soilless mixtures are widely used. Two or more culture media can be combined together to form an optimized growth mixture. The soilless medium can be used in automatic hydroponic facilities or in a single container for manual watering.

Step 6: Plant container

The type of container you use will depend on the size of the media, system and plant. For flood discharge, the tray-type hydroponic system can use small net pots filled with pebbles or just a large piece of rock wool to grow many small plants, while “super soil” planting can use a 10-gallon nursery to grow some large plants.

Cheap options include disposable plastic bags or cloth bags with holes, while some people choose to spend more on “smart pots”, these containers are designed to enhance the airflow to the root area of the plant. Many people planted the first cannabis plants in five-gallon barrels.

Drainage is key, because the cannabis plant is very sensitive to full water, so if you want to reuse another container, make sure to drill a hole in the bottom and then place it in the tray.

Step 7: Cannabis plant nutrition

Compared with most common crops, growing high-quality cannabis flowers requires more fertilizer or nutrition. Your plant needs the following main nutrients (collectively called macronutrients):

  • Nitrogen (N)

  • Phosphorus (P)

  • Potassium (K)

These micronutrients are also needed, although the amount is much smaller:

  • Calcium

  • Magnesium

  • Iron

  • Copper

If you are not using pre-fertilized organic soil mixtures, you will need to use proper nutrient solution to raise the plants at least once a week. These nutrients are sold in concentrated liquid or powder form, intended to be mixed with water, and are usually formulated for vegetative growth or flower growth. This is because the ever-changing macronutrient requirements of cannabis during its life cycle require more nitrogen during vegetative growth and more phosphorus and potassium during bud production.

Most macronutrients are sold in two-part liquids to prevent certain elements from settling (incorporated into inert solids that plants cannot use), which means you need to buy two bottles (part A and part B) And two bottles for growth, and a bottle of micronutrients. In addition to these basics, the only other nutritional product you may need to purchase is Cal/Mag supplements, because some strains require more calcium and magnesium than others.

After purchasing the necessary nutritional products, simply mix them with water according to the label instructions and then water the plants with this solution. You should always start at half intensity, because the cannabis plant burns easily. Overfeeding the plants is always not enough to feed the plants, and as time goes on, you will learn to read the plants for signs of defects or overdose.

Obtaining a pH meter is important so that the pH of the water can be checked when mixing nutrients. The pH of cannabis in soil is between 6 and 7, and the pH in hydroponic medium is between 5.5 and 6.5. Making the pH outside this range will cause nutrients to lock in, which means your plants cannot absorb the nutrients they need, so make sure to test your water regularly and make sure that the nutrient mixture fed to the plants is within the required range.

Step 8: Watering the cannabis plant

Some water contains a lot of dissolved minerals, which may accumulate in the roots and affect nutrient absorption, or it may contain fungi or other harmless pathogens to people, but may cause root diseases.

In addition, the chlorine content in the water supply in some places may be high, which may be harmful to beneficial soil microorganisms, so irrigation water needs to be filtered.

The most important thing about watering is not to flood. When conditions are too humid, cannabis plants are vulnerable to fungal root disease, and over-irrigation is one of the most prone mistakes for newborns.

Overwatering or Not? How to Watering Your Cannabis Plants

The frequency of watering plants will depend on the medium used, the size of the plants and the ambient temperature. Someone will wait until the leaves at the bottom of the plant begin to droop before watering.

With the accumulation of experience and knowledge, you will change your growth space and equipment to better adapt to your specific environment, growing technology and growing specific pressure, but this article will provide you with a solid knowledge base in order to Start with the right footsteps.

VANQ LED hvae 10 years experience on LED grow lights, we also provide customized service. Have any need please feel free to contact us.

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