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Indoor Growing - The Definitive Guide To Gardening Inside

Indoor growing is becoming more and more popular, especially as technology makes it easier.

There are so many reasons you should consider growing plants indoors

Maybe you want to continue growing your favorite plants during the cold winter months.

Or, you want to create your own growing environment to get bigger yields and more potent flower.

Maybe you just want a new challenge - and growing plants indoors is just that.

We are going to teach you everything you need to know about indoor growing.

By the end of this guide, you will know everything you need to grow huge plants in the comfort of your own home!

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Indoor Growing - The Definitive Guide To Gardening Inside

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Indoor growing is becoming more and more popular, especially as technology makes it easier.

There are so many reasons you should consider growing plants indoors

Maybe you want to continue growing your favorite plants during the cold winter months.

Or, you want to create your own growing environment to get bigger yields and more potent flower.

Maybe you just want a new challenge - and growing plants indoors is just that.

We are going to teach you everything you need to know about indoor growing.

By the end of this guide, you will know everything you need to grow huge plants in the comfort of your own home!

Why you should consider indoor growing

When you think of growing plants, you probably think of a small garden in the backyard.

Maybe you picture a little plot of land in a discreet location with a farm. But, indoor growing is something everyone should consider.

There is nothing better than having access to flower when you know exactly where it came from and how it was grown. Growing your own organic, pesticide-free plants is the best way to go.

Sure, you could grow outdoors too, but there are a few reasons we prefer indoor growing.

Complete control over the indoor growing environment

When you grow outdoors, mother nature provides excellent conditions for cultivation, assuming you grow during the right season for your plant.

When you plant in spring or summer, your plants go through their natural growth cycle and are ready for harvest around October as the seasons start to change.

Sometimes, unpredictable weather, poor access to sunlight, and other things can hinder your outdoor grow, and there is really nothing you can do about this.

Plus, when growing outdoors, there is not a ton you can do to prevent pests and diseases.

There is nothing stopping caterpillars from munching on your leaves, or the wind from carrying mold spores to your plant. Some issues will inevitably arise.

These are some of the problems that don't exist when growing indoors because you have complete control over the growing environment.

You get to meticulously monitor temperature and humidity levels, along with lighting periods.

If you just follow best practices, you can supercharge plant growth and bud development compared to outdoors. Plus, the outcome of your grow is 100% dependant on you - no leaving anything to chance.

You can grow indoors year-round

Growing outdoors is a once per year type of thing. Because you are playing by mother nature's rules, you plant in the spring and harvest in the fall.

This is only one growth cycle, and that harvest is supposed to last you all year? That is not only unfeasible, it would be boring!

When you grow indoors, you can manipulate the growth cycle to harvest faster (every 8-12 weeks), and you can grow during spring, summer, fall, and winter! Don't let the weather dictate your growing schedule.

The quality of indoor plants

Because you have complete control of the growing environment, you can produce way more potent flower than outdoors.

The idea of "boutique" grows is that because you are focusing on fewer plants and providing them more attention, you can supercharge their development.

This leads to more aesthetically pleasing flower, with better aroma and taste, on top of elevated potency.

This isn't to say that indoor flower is inherently more potent than outdoor flower - it takes experience and dedication to indoor growing to achieve these results.

If you aren't a good grower, you won't grow awesome plants - that should go without saying.

Let's talk about the things you need to consider when planning your indoor grow.

Choosing a location for indoor growing

Let’s start from square one - choosing a location for your indoor grow. This is incredibly important to your success.

Your grow room location needs to be easily accessible by you, but not others, and especially not pets or unwanted pests.

Your location also needs to be easily controllable from an environmental standpoint, so you can monitor temperature, humidity, air flow, etc.

Plus, your location will determine how many plants you can grow, and how they grow. Let’s discuss the dimensions of your grow space.

Determining the size of your grow room

indoor growing room

You need to budget space in your grow for working on your plants, along with storing supplies and equipment, and the final height of your plants.

Vertical height requirements are typically around 8’ but sometimes a 9’ or 10’ ceiling is necessary when using high wattage & high intensity grow lights.

If the container your plant sits in is 12” tall, and your grow light reflector is 12” tall and needs to be hung 30” above your plants’ canopy then you’ve already consumed 54” (4.5ft) of vertical space.

In a room with an 8ft tall ceiling, you would have 42” (3.5ft) of ‘safe’ vertical growth space for the plants. In a 6ft tall room, you would have only 18” (1.5ft) of available vertical growth space.

If you are limited on vertical space, you will likely want to grow many smaller plants vs fewer, larger plants that will grow much wider and taller and consume more space in your grow.

Beginners often make the mistake of cramming too many plants into a small area. This forces the plants to fight for light energy which creates a dismal yield filled with small, airy flowers.

In most cases, it is better to grow fewer plants that have enough available light energy to produce a strong yield.

This balance of the number of plants in your grow room vs the available grow space and light is critical to the success of your garden’s yield.

Factor in power and water for your grow room

You also need to make sure you have an adequate power source for your grow room equipment. More often than not, this won’t be a problem. You can use extension cords if need be.

But, certain equipment, such as heavy-duty grow lights, air conditioners, dehumidifiers, etc. may need a 240v outlet. You’ll need to plan for this accordingly.

Similarly, think about how you’ll get water in your grow room. Is there a faucet nearby, or a hose? If possible, you want to avoid lugging heavy, 5 gallon buckets of water around the house.

Examples of common indoor growing spaces

You can turn any part of your house into an indoor growing space. Sometimes you can reverse engineer this process and determine how many plants you want to grow, and find a space accordingly.

However, more often than not, your indoor grow will be limited by space.

You may be forced to grow in a small bedroom, a section of your garage, or even a closet.

Regardless, you can grow some awesome plants, it’s just about making the most of what space you have. Here are some common indoor grow designs:

2' x 4' indoor grow room

2' x 4' grow tent

4' x 4' indoor grow room

4' x 4' grow tent

4' x 8' indoor grow room

4' x 8' tent

10' x 10' indoor grow room

10 x 10 grow tent

Or, you could try setting up a perpetual grow - but if this is your first indoor grow, you should probably just focus on one set of plants, in one growth stage.

Once you get a bit more experienced, you can try one of these perpetual harvest setups:

4' x 4' veg chamber, 4' x 8' flowering chamber

4' x 4' veg chamber, 4' x 8' flowering chamber

4' x 8' veg chamber, 4' x 8' flowering tent setup and design

4' x 8' veg chamber, 4' x 8' flowering tent setup and design

If you have a lot of space, and want to get serious, you can design an incredible growing space. Check out this perpetual garage grow example below. It features a veg tent, two different flower chambers, a drying section, and it still has room for storage, water, and a car!

4' x 8' veg chamber, two 8' x 8' flowering chambers, and 4' x 8' drying area

4' x 8' veg chamber, two 8' x 8' flowering chambers, and 4' x 8' drying area

As you can see, the sky's the limit when it comes to your grow room setup. If you have a ton of space and want to get serious, you can set up an awesome indoor grow. For more inspiration, check out our post on grow room design.

If you’re growing indoors, do you really need a tent?

We cannot recommend grow tents enough. These are an absolute necessity for indoor growing in most cases.

They make gardening indoors so easy and provide a ton of other benefits. Here are some of the reasons we suggest everyone uses a grow tent indoors:

  • They create a separate environment for your plants. This helps you manage temperature, humidity, and airflow super easily. Without a grow tent, you’d need to set up a ventilation system in your room, and it’d affect the environment in your house.
  • Grow tents also contain the mess of indoor growing, including the smells of your plants. You won’t need to worry about any nutrient spills, soil mishaps, or plant matter falling onto your carpet or hardwood because the grow tent is spill-proof and makes cleaning messes easy. Plus, they do a great job containing the smell of your indoor grow. The last thing you want is to have guests over and the first thing they’re greeted with is your pungent indoor grow. Or, worse, those smells could extend out of your house to your neighbors.
  • The reflective mylar material of a grow tent maximizes the amount of light your plants receive. You’re going to spend the money on a grow light and the electricity to run it, so you may as well get the most out of it! Grow tents also prevent light from getting in and out of the tent.

These are just a few of the reasons you should grow indoors with a tent. You will set yourself up with the best chance of success this way.

Once you have an idea of what you want your grow room to look like, its just a matter of grabbing a tent that works with that space. Check out this video below if you need more reasons to buy a grow tent!

You can check out our grow tent buying guide if you aren’t sure which tent is right for you. Once you have an idea of what tent you want, it's time to choose a light.

Choosing a grow light for indoor growing

Without the sun, your plants need a source of artificial light to grow. This is where your grow lights come in.

There are so many different types of grow lights, and it can get overwhelming for a first-time buyer.

We are going to break down each lighting type and help you choose the best one for your indoor grow.

Metal Halide (MH) and High-Pressure Sodium (HPS) Grow Lights

Metal Halide (MH) and High-Pressure Sodium (HPS) grow light

MH and HPS grow lights are the most traditional grow lighting technology, and while they are slowly becoming outdated, manufacturers are still evolving this technology to make it relevant to today’s indoor grower.

Here are some of the pros and cons of this style of lighting:


  • Very intense lights
  • Excellent watt-to-lumen output ratio
  • Inexpensive


  • High heat output
  • Not very efficient (monthly energy bill)
  • Bulbs don’t have the longest life span (replace every 9-12 months)
  • Need two different fixtures - MH for veg and HPS for flower

These lights are great for beginners who want a simple, inexpensive light and don’t mind switching them out between veg and flower.

But, there are newer technologies that produce insane yields more efficiently, without the heat.

Ceramic Metal Halide (CMH) Grow Lights

CMH grow light (ceramic metal halide)

CMH grow lights are a variation of HID technology, similar to MH/HPS lights.

But, this newer technology runs much more efficient and produces less heat.

These lights are quickly becoming many grower’s favorite source of light, but they are definitely not for everyone.


  • Incredibly energy efficient, and do not produce a ton of heat
  • Very powerful, yet can still be placed close to plant canopy without burning or bleaching
  • Full-spectrum for seed - harvest growth
  • Very long bulb life
  • Insane Lumen and PAR output, generating huge, potent yields


  • High startup cost
  • Spectrum isn’t as optimized as LEDs

The only real complaint that can be made about CMH grow lights is the startup cost.

These are pretty pricey, so new growers may not want to shell out for one of these.

But, if you plan on growing for years to come, this can be an awesome investment and you won’t be disappointed. However, we haven’t even covered the most popular indoor grow light yet.

Light Emitting Diode (LED) Grow Lights

LED Grow Light

LED grow lights are the latest and greatest in the indoor growing industry.

These lights simply cannot be beaten from an efficiency and performance standpoint.

They can also be a bit expensive, but you can see a direct ROI from these in the form of energy savings.


  • These lights provide unmatched intensity per watt
  • Adjustable, full-spectrum, sometimes including IR and UV light that can have profound effects on your plants
  • Most energy-efficient lighting technology
  • Long lifespan - no need to replace bulbs!


  • High startup cost
  • Not quite as powerful as HIDs (still more powerful per watt, though)

While these lights can be expensive, the savings you get on energy should provide a return on your investment.

Plus, most grower’s agree that LEDs produce denser, stickier flowers than HID styles of lighting. If you are serious about indoor growing, use an LED light!

Want our recommendations? Check out our Best LED Grow Lights article.

Fluorescent grow lights - T5’s and CFL’s

Fluorescent T5 Grow Light

This style of lighting is a bit different in that you shouldn’t use one for full-cycle growing.

Fluorescent light is incredibly efficient and does not produce heat, but its also not suitable for taking a plant from seed to harvest.

However, if you are looking for a light for propagation and veg, you cannot go wrong with a T5 or CFL fixture.


  • Very budget-friendly
  • Incredibly efficient
  • No heat production
  • Awesome for propagation


  • Not very powerful
  • Not ideal for taking a plant through flower

One thing to note is that you also need a light timer or controller. This will connect to your grow light, and you can set up your daytime and nighttime periods.

On these set intervals, your grow light will turn on and off automatically. These are super convenient, and something we consider a necessity. They not only make your life easier, but they also cut down on human error.

Once you have chosen a grow light technology, you can determine your growing method.

Determining your indoor growing method - hydroponics vs soil

There are two ways you can grow plants indoors - with pots and soil, or hydroponics.

The method you choose will dictate what type of nutrients you use, along with how much effort you need to put into your grow.

Traditional gardening with soil and pots is definitely more popular, but hydroponics has a ton of benefits too.

Which one is right for you will depend on your budget, indoor growing experience level, and more. We’ll quickly cover some basic information on each, along with the pros and cons.

Growing in soil

growing in soil indoors

Growing soil plants indoors is more common and much easier. There are a ton of different soils you can choose from, some better than others.

Stay away from cheap discount soils, and definitely don’t go outside and fill up a bucket with dirt. Using good soil will help your plants absorb nutrients better, and provide better drainage.

When growing in soil, you’ll need to either select one large pot to take you from seed to harvest, or you’ll need to transplant your plants as they grow.

If you are looking for a low maintenance grow, you can get away with using one pot for the entire growth cycle, but it won’t be ideal.

Your small plant may struggle to grab nutrients in such a large pot with a small root system. If you want the best results, you should use different pots for different stages of growth.

You can place clones or seedlings in a very small pot, and after a few weeks of veg, transplant them into a larger pot, and then maybe once more before flower.

Transplanting can stress your plant a bit, but if you do it right, it won’t result in any real problems.


  • Growing in soil is more forgiving than in hydroponic systems. Diseases typically spring up slowly so you have time to investigate
  • Super simple: put the plants in the soil and water them every couple of days. Growing in soil requires less care and maintenance than a hydroponic garden.
  • The pH levels will remain relatively stable even if fed with a nutrient mixture that is too high or too low since the soil will act as a buffer.
  • Potted plants can be easily moved and relocated.
  • Much cheaper than a hydroponic system
  • The opportunity to grow hydroponically


  • Soil plants grow slower than those in hydroponic systems.
  • Soil plants produce less of a yield than hydroponically grown plants, and the yield may be less potent.
  • Container-grown plants can become root-bound over time if they are not transplanted into a larger pot, stunting or stopping growth altogether.
  • Soil gardens are more prone to pests and diseases

Not sure which soil is right for you? Check out our post on the different types of growing media! If you are looking for a specific recommendation, you should check out our review of the top soils of this year.

Growing hydroponically

Hydroponics is a method of growing that omits soil. Instead, seeds or clones are started in a rockwool or coco cube to harden off and develop roots. Then, they are placed in a hydroponic system.

Here, a hydroponic grow medium such as coco, rockwool, perlite, hydroton, or clay pebbles/growstones may be used to support the plant and anchor the roots in place. But, the medium needs to be inert.

The premise behind hydroponics is that the plant’s roots has access to all the oxygen it needs, along with a super-concentrated nutrient solution. This results in accelerated growth rates, and insane yields.

Growers who choose to grow hydroponically need to be much more aware of the pH, parts per million (ppm) or total dissolved solids (TDS) and the temperature of their nutrient solution.

Failing to dial these in will result in slow, sickly growth, or possibly the loss of the entire crop.

pH should be kept between 5.5 and 5.9 for optimal growth while the temperature of your nutrient system should be kept below 70F to prevent unwanted algae and pathogen buildup which can be harmful. We’ll touch more on this topic later in the series.

There are quite a few different hydroponic systems - some better than others.

If you are growing in a tent, you'll need to use a smaller system. You'll probably be best suited with an ebb and flow system or a DWC system. Read our Hydroponics 101 guide for more information!


  • Diseases and nutrient deficiencies/toxicities can be easily spotted and quickly remedied. If they are caught in time, you can alleviate these within hours.
  • Plants grow faster which can cut down on vegetative growth time which allows you to flip the plants to flower quicker.
  • Hyper control over nutrient levels will typically result in a much larger yield than in soil grows.
  • Depending on the hydroponic system, the entire grow could be almost 100% automated.


  • More equipment is needed to grow hydroponically. You need to maintain pH, water temperature and nutrient levels.
  • Hydroponics has a steep learning curve. The amount of water provided needs to be completely controlled - if the roots don’t get ample oxygen, they will shrivel and die. If an air pump fails and your roots are sitting in stagnant water the entire crop will be lost in a matter of hours.
  • Just as quickly as plant issues can be spotted, they can also take over. You need to check your grow at least once a day to keep an eye on any developing problems.
  • If not installed properly an indoor grower may flood his entire room, house or basement. This can cause problems for those of us trying to remain ‘stealth.’
  • Hydroponic systems are pretty expensive - so is the equipment you need to optimize them.
  • Hydroponic systems need to be clean at all times. The system prevents system clogs and the ability of pests/molds to overtake the system.

At the end of the day, this is a pretty simple decision. If you are a new grower, stick with soil. If you have some experience, a bigger budget, and are up for a challenge, maybe try hydroponics!

Just know that you will have to put in more work. Once you’ve made your choice, the next step in putting your grow together is figuring out your indoor growing environment.

Looking for a recommendation on a system? Check out our yearly review of the best hydroponic systems.

Understanding the importance of the environment for indoor growing

Because you are inside, you are responsible for controlling the indoor growing environment.

This means temperature, humidity, CO2 levels, and airflow. When you grow outdoors, mother nature controls these, and you don’t even have to think about them. Things can get a bit complicated here, but we’ll try to keep it simple.


The temperature of your indoor grow is one of the most important environmental factors you’ll need to monitor.

Excess heat can lead to mold and mildew production, and a slow in plant growth. On the other hand, if your grow room is too cold, you’ll also experience a slow or complete halt in growth.

The ideal temperature range changes as you move from one stage to the next.

For example, clones and seeds like it a bit warmer than plants in veg. Then when you move to flower, temperatures should drop a bit more. Here are the recommendations:

  • Propagation: 72-80°F
  • Veg: 68-78°F
  • Flower: 68-76°F

Battling heat in the grow room isn’t always easy, but its certainly doable. Grow room air conditioners are great, but if you are a hobby grower with a small tent this is not feasible.

You can set up a thermometer to help you monitor temps, and you can use circulation fans in conjunction with your ventilation system to expel hot air and bring in cool, fresh air.

We’ll dive a bit deeper into this shortly, but first, let’s talk about moisture.


The next most important environmental factor you need to monitor is humidity.

Humidity relates to how much moisture is in the air, and if it extends out of the ideal range in either direction you’ll experience problems.

Plants do need a certain amount of moisture to grow, so you don’t want to suck all moisture out of the room.

But, excess humidity can lead to mold and mildew development. Here are our recommendations for the different stages of growth:

  • Propagation: 70%
  • Veg: 40-60%
  • Flower: 40-50%

There are two super simple ways to manage humidity in your grow room, but they are pretty expensive. Humidifiers can add moisture, and dehumidifiers can remove moisture.

There is a relationship between humidity and temperature, and an ideal ratio across different stages of plant growth.

This is known as vapor pressure deficit. If you are looking for a more advanced look, check out our guide on VPD.

But, the most cost-effective way to manage humidity when growing indoors is with a good ventilation system.

We’re not quite ready to get into the ventilation system yet, but we’ll cover that soon. First, let’s talk about CO2.


indoor growing environment chart

Carbon Dioxide, also known as CO2, is crucial to plant development. It is used for photosynthesis, and supplementing your grow room with CO2 can lead to insane growth rates.

If you are considering using CO2 to improve your grow, it's important to understand the relationship between CO2 and light.

If you are using lower-powered grow lights, such as fluorescents, you won’t get as impressive results by supplementing with CO2. This is because your low powered light is the limiting factor in your grow.

But, if you use super powerful lights, CO2 will be the limiting factor. You can increase the PPM of CO2 in your grow to greatly increase the growth rate and yield of your plants.

There are a few ways you can increase CO2 in your grow room. Which one is right for you will depend on whether you are in a grow tent or not. You can use CO2 burners, CO2 tanks and regulators, or even little CO2 bags.

This is supposed to be a basic guide on indoor growing, so we won’t go too in depth on this more advanced topic.

But, if this sounds like something you are interested in, you can check out our complete guide to supplementing your grow with CO2.

The importance of airflow for indoor growing

One of the best ways to manage temperature and humidity is with proper airflow. But, getting the air moving in your grow room or tent is important for more than just one reason.

There is an old saying that you want your plants to “dance”. A gentle breeze running through your plants can strengthen stems, and discourage pests and diseases from infesting. Stagnant air is no good when it comes to indoor growing.

We highly recommend you have at least some level of air circulation in your grow. If you are growing in a bigger room and have space for it, you can use any kind of circulation fan.

If you are growing in a tent, like we recommend, you probably won’t be able to fit a bulky floor or pedestal fan. Instead, you can use little clip-on fans.

We recommend grabbing a couple of these, so you can hit your plants from different angles. Speaking of airflow, let’s dive into the importance of your ventilation system.

How to set up a ventilation system for your grow room

indoor grow room ventilation system

When it comes to indoor growing, your ventilation system is one of the most important components.

Without a means of removing hot, stinky, stagnant air, your plants will greatly suffer. There are two types of ventilation systems: passive and active.

Passive ventilation systems do not feature an intake, just an exhaust system. On set intervals, the inline fan kicks on and pulls hot, old air out of the growing space, and fresh air comes in passively.

On the flip side, an active ventilation system includes both an exhaust system and an intake system.

While the exhaust system removes old air, the intake system actively brings in fresh air. Most of the time, a passive ventilation system is all you need for indoor growing.

If you need any help with this part of setting up your grow, check out our guide on putting together your ventilation system. If you want a more comprehensive view of grow room atmosphere, visit our blog!

By now, you should have your grow tent, light, growing method, and ventilation system. If you still need to grab these supplies for your grow, check out our grow room builder.

This awesome tool helps you select a tent, and then provides you with options for lighting, ventilation, and accessories based on the tent you choose.

Or, you can grab one of our preconfigured grow tent kits if you don’t want to build your own. Once you have everything you need, its a matter of putting it together.

Setting up your grow tent kit

When you grab a grow tent kit at Hydrobuilder.com, putting it together is super easy. We can break down this process into a few simple steps.

  1. First, you need to set up the grow tent itself. This is as simple as putting poles together and putting the tent canvas on.
  2. Step two is putting together your ventilation system. This is probably the trickiest part of setting up your grow tent kit. Start by preparing your carbon filter, and then hanging it in your tent (or placing it on the ground, or outside the tent). Then, attach your inline to your carbon filter. The next step is just attaching your ducting and feeding it outside the tent port. Lastly, set up your fan speed controller and configure your exhaust intervals.
  3. The third step is hanging your grow light. This is super easy, and all you need to remember here is the height you need to hang your light at. Then, configure your lighting timer and set your on and off cycles.
  4. Once you have that done, its just a matter of adding in any accessories, bringing in your pots/soil or hydro system, and checking for any issues!

This was a super simple step by step guide, but we have an in depth guide to setting up your grow tent if you want more information. You can also check out this video below for a visual guide!

At this point you are just about ready to start your indoor grow. Before you start popping seeds or grabbing clones, we need to talk about the importance of water.

The importance of water for indoor growing

Water is the basis of your indoor growing system. Yes, you’ll be using nutrients too, but the water you use to dilute them is even more important sometimes.

We are going to cover the importance of water quantity AND water quality.

Overwatering and underwatering your plants

One of the biggest mistakes new growers make, other than overfeeding, is overwatering. On the flip side, underwatering your plants will cause problems too.

If you’re growing in a hydroponic system, you won’t really need to worry about over and underwatering. You’ll have a controller to monitor the water levels.

But, if you’re growing plants indoors in soil, you’ll be manually watering them. The last thing you want is to waterlog your plants. This can starve them of oxygen, potentially killing them.

The best way to tell when you need to water your plants is paying attention to the soil

Stick your finger in the soil an inch or two, and if its dry at the tip of your finger, its time to water. If its still damp, you are probably good to wait another day or so until its dry.

It sounds simple, but you should check out our guide on how to properly water your plants if you're a first time grower. It will save you from the most common mistake a new grower makes.

How the quality of your water affects your indoor plants

Just as important as how much water you give your plants is the quality of that water.

These days, tap water is riddled with chemicals and additives that may not be harmful to us humans but can wreak havoc on our plants.

We recommend you find out what's in your water, and examine the calcium, magnesium, potassium, pH, and water hardness.

This will give you an idea of whether your water is excess or deficient in these essential nutrients and metrics. But, the most important thing to look for is the level of chlorine.

If you get your water from a public or community water system, yearly reports are published on water quality.

These are freely available to the public and can usually be found on your water utilities website or by calling your utility company.

The EPA provides a list of phone numbers for water utility providers on their website. The Safe Drinking Water Act requires public drinking water to comply with certain EPA standards of quality.

You may need to find a water filter that can remove chlorine and chloramine - which can harm your indoor plants. You can learn more about RO filters and dechlorinators here.

Plant Nutrition

plant nutrition

If you are a first-time grower, you may not know the importance of nutrients yet.

But, make no mistake, you need them if you want to grow big plants with heavy yields. Let’s cover the basics of plant nutrition quickly.


Macronutrients are the most important nutrients to your plants - and are needed in the highest concentration.

Chances are if you've ever looked at any kind of plant fertilizer or nutrient line, you have noticed three numbers separated by hyphens.

These three values tell us the percentage of each macro nutrient contained within the product. The first number represents Nitrogen (N), the second represents Phosphorous (P), and the third Potassium (K).

For example, Fox Farm Grow Big Liquid Concentrate has an NPK of 6 - 4 - 4. This means it is Nitrogen dominant, with equal proportions of Phosphorous and Potassium. But how do these nutrients affect your plants?

  • Nitrogen - critical at all stages, but especially veg. It promotes photosynthesis, and produces chlorophyll. During the veg period, you will use Nitrogen dominant nutrients to promote robust, leafy growth.
  • Phosphorus - critical at all stages, but especially flower. Just as your veg nutrients are Nitrogen dominant, your bloom nutrients will be Phosphorous dominant. On top of promoting big flowers, it results in terpene production, contributing to the smell of your buds!
  • Potassium - critical at all stages, responsible for rooting, resistance to disease/pests, and overall growth. You'll see pretty even levels of this nutrient through veg and flower.

Secondary Nutrients

These nutrients are super important as well, but are needed in lower concentrations.

These nutrients are commonly used as supplements and additives throughout your plants life to round out your feeding schedule, but they also can be used to combat deficiencies that arise.

  • Magnesium - helps plant utilize other nutrients, along with producing carbohydrates and sugars that help your plant produce flowers.
  • Calcium - This is an essential nutrient for helping your plant develop strong cell walls and roots. It leads to strong branches that can support heavy flowers.
  • Sulfur - This nutrient can help produce chlorophyll in your plants, leading to robust vegetative growth and root development.


Micronutrients are similar in plants and humans - they are needed in tiny amounts, but deficiencies or toxicities of these micronutrients can cause a myriad of issues.

Here are the 8 most important micronutrients, but there are many more:

  • Zinc (Zn)
  • Manganese (Mn)
  • Iron (Fe)
  • Boron (B)
  • Chlorine (Cl)
  • Copper (Cu)
  • Molybdenum (Mb)
  • Silicon (Si)

Many feeding schedules contain a micronutrient supplement, just like you might take a multivitamin.

These don't really promote plant growth directly like macronutrients and secondary nutrients. Instead, they just contribute to plant functions - such as photosynthesis, nutrient uptake, and much more.

Choosing the right nutrients for indoor growing

Cultured Solutions nutrients

Most nutrients do the same thing, but some are formulated stronger or purer than others.

There are so many brands and products, so stick to one of the most popular brands if you are unsure: Botanicare, Cultured Solutions, General Hydroponics, Fox Farm, Earth Juice, Emerald Harvest, etc.

Grabbing a nutrient package is the best way to shop for nutrients. These nutrient packages are meant to work synergistically within your plants, and the feeding schedule makes it so simple.

There are also tons of supplements and additives you may want to bolster your nutrient regimen, such as growth enhancers, bloom boosters, sugars and sweeteners, etc.

But, something you may be wondering about is the difference between synthetic and organic nutrients.

Obviously synthetic sounds unhealthy and has a bit of a negative connotation, but are synthetic nutrients really that bad? Let's dive in.

The difference between synthetic and organic nutrients

It goes without saying that organic plant nutrients are cleaner. Plus, you'll be leaving a smaller footprint on the environment.

Since you'll be consuming your flower at some point, it's fair to say that organic nutrients are better.

Organic flower tastes better, smells better, and is safer for human consumption. But does that mean synthetic nutrients are bad?

You may associate "synthetic" with man-made, or unhealthy. But, in many cases, synthetic nutrients are derived from organic sources.

Plus, growing with synthetic nutrients is much easier than with organics. Organic nutrients absorb slower, so deficiencies/toxicities will take longer to notice and correct.

If you are growing hydroponically, you have to use synthetic nutrients. Organic nutrients are notorious for clogging hydro systems.

If you want an easier, low maintenance grow, synthetic nutrients are your best bet. But, if you're in this to grow the best plants, and are concerned with what you put into your body, stick to organic.

If you are looking for a specific recommendation depending on how you plan to grow, check out our review of the best plant nutrients this year.

Monitoring pH in your grow

When you feed your plants, you'll need to check the pH after mixing nutrients.

This is because the pH of your nutrient solution affects your plant's ability to uptake them. This is one of the most common mistakes new growers make - not balancing their pH.

So, if you notice symptoms of nutrient toxicity or deficiency, it may be a pH issue.

When growing in soil, shoot for a pH between 5.5-6.5. In hydroponics, you need to a be a bit more precise, and shoot for a pH of 5.5-6. Later on, we'll cover how to actually feed your plants and balance pH.

By this point, you have your entire indoor grow setup, you have an idea of how you’ll get water to your plants, and you have your nutrient package.

Most of the logistical work is done, and now you can get started growing! Let’s discuss how you will grow your plants - from seeds or clones.

Starting plants from seed or clone - which is right for you?

There are two main ways you can get started with indoor growing - from seeds or from clones.

There are pros and cons to each, and we’ll describe each method before giving you our advice.

Starting your indoor grow with seeds

Starting your indoor grow with seeds

Starting seeds is a great way to start your indoor grow, because you can carefully select genetics and a wide variety is available. Plus, most growers believe a seed will yield more than a clone will.

There are a few different ways to start seeds indoors. You can use the simple paper towel method, where you place a few seeds inside a damp paper towl and place it on your windowsill.

Or, if you want a more fool-proof, advanced method, you can use a complete seed starting kit. These give you the best chance of success when starting from seed.

If this sounds like something you’re interested in learning more about, you can check out our complete guide to starting seeds.

However, germination isn’t for everyone. This adds a few weeks onto your grow, and can be more challenging compared to starting your indoor grow with clones.

Starting your indoor grow with clones

If you choose to start with clones, you’ll need a reliable supplier of clones. Maybe you have an experienced friend who has a mother plant and they are happy to provide you with a couple of clones.

Otherwise, you’ll need to find a licensed supplier, which can be tricky. Check with local dispensaries, as many of them stock clones.

Once you have clones, you need to keep them alive while they harden off.

A cloning machine will provide the perfect environment for these baby plants, and once they’ve developed a strong root system, you can transplant them into a bigger pot with soil or into your hydro system and you can get started growing seriously.

Starting your indoor grow with clones allows you to jump ahead a few weeks in your grow, and skip many of the difficult steps of germinating seeds. You can learn more about taking and caring for clones in this article.

We recommend that you start your grow with clones, at least at first. This is much easier for beginners and decreases your time to harvest. Regardless of how you start your plants, the goal is to get them to start rooting.

This can take a few days to a few weeks, so don't get discouraged if its not an overnight success. Its also unlikely you'll see a 100% success rate with propagation, which is why we recommend starting more seeds and clones than you need.

You can do certain things to speed up the rooting process and increase your chances of success, such as using rooting solutions. If you used a rockwool cube or starter plug, you'll eventually see roots popping through the surface.

Once there are a few of them, the babies are ready to be transplanted into a pot with soil, or into your hydro system. You can begin vegging them, and the fun of indoor growing begins!

The Veg Stage Of Indoor Growing

The first phase of growing is known as the vegetative phase, or veg for short. Here, the focus is on growing as many branches, growth nodes, and leafy foliage as possible.

The more branches your plant has, the more growth nodes it’ll develop. This is where your flowers will bloom once you transition into that stage.

Keep your plants on an 18 hour on, 6 hour off light cycle during veg. This simulates the long, sunny days of summer.

You can veg your plants as long as you’d like, but the longer you veg the bigger your harvest will be. We recommend you start with a 4-6 week veg period.

While your plants veg, they will grow rapidly. But, there are a few things you can do to make them grow even faster, and set yourself up for an even more bountiful harvest. Training techniques allow you to manipulate the way your plant grows, so you can make a wider canopy.

You can also prune your plants in a way that results in more large colas, as opposed to one large cola dominating the plant. Check out our guide to plant training for more in-depth information on this topic.

Honestly, if you are looking for a lazy grow and don’t want to put a ton of work in, you don’t need to practice any sort of training and pruning techniques. Your plants will start to flower once you flip the photoperiod regardless!

But, we know you've read this far because you want to grow huge, awesome plants. So, we are going to provide you with a checklist on how to make the most of the veg period.

Week 1 Of Veg

During the first week of veg, you won't feed your nutrients a full strength nutrient schedule. Your plants are still tiny, so you'll only need around 250-700 ppm.

If you started seeds, use the lower end of that range, and if you have clones, you can bump it to the higher end.

You'll water your plants twice this week, once with nutrients and once without. Be sure to pH your water before feeding regardless of if its nutrients or plain water.

While your plants are this small, keep your light between 18-24" above your canopy, or whatever your light manufacturer recommends.

There are little things you should be doing every day when growing indoors. We have a daily, weekly, and monthly checklist you can follow to make sure you aren't missing any important tasks. You can print this out, and stay on top of your grow!

How to adjust pH for indoor growing

Since you are going to start watering your plants this week, you need to have a good idea of how to adjust the pH! Its actually incredibly simple, you just need a few things: a pH meter and pH up/down.

When you stir your nutrients or fill your bucket with water to feed your plant, stick your pH meter in the liquid and stir it around. If it says your pH is too high, add a few drops of pH down.

If your pH is too low, add some pH up. A little bit goes a long way here. You can keep testing and adjusting until the pH is right where it should be - between 5.5 and 6.5 (for soil).

Week 2 Of Veg

You'll be surprised at how your plants can grow in just one week. While they're young, you'll see substantial gains in height and foliage development. Since they've had more time to harden off and grow, you can feed your plants between 550-700ppm this week.

The first two weeks are all about allowing your plants to acclimate to their new environment, developing a root system, and simply keeping them alive! But, its a good idea to start thinking about training and pruning. Let's go over some best practices.

Why prune and train your plants?

There are plenty of reasons you should put in the effort to train and prune your plants.

You can dictate the way they grow, and allow light to get into areas of your plant that normally wouldn't. It also results in more even growth, as opposed to one large cola dominating the plant.

If you are in a space-restricted indoor grow, training your plants allows you to get the most out of your space.

How to prune your indoor plants

There are lots of different ways to go about this. Topping is very popular, and is the act of cutting off the top-most shoot of growth. This leads to the formation of more bud sites there, as opposed to just one.

Or, you could try FIM'ing. This is a style of pruning where you cut off 2/3 of the tallest growth shoot, you can produce 4 bud sites!

Check out our complete guide on pruning your plants to increase yields. This will give you a more detailed understanding of the different strategies you can follow.

How to train your indoor plants

A super simple training technique is defoliation. This involves removing excess fan leaves.

In some cases, these fan leaves do nothing more than steal energy from the rest of the plant and prevent light from reaching certain areas. So, plucking these leaves off can result in some awesome growth.

Low-stress training doesn't involve any sort of pruning, but rather bending stems. You can bend stems out away from the middle of the plant, sort of opening it up in a sense.

Tie these stems lightly to the outer edge of the pot or to stakes. You want to do this early on when branches are still bendable, otherwise, they will snap. Doing this results in a wider canopy, and more bud sites.

If you want to get serious with your plant training, you could try the Sea Of Green (SOG) method. This strategy results in the widest canopy possible, and is the best way to grow if you are limited on height.

You follow the same principles of low-stress training, bending branches back and tying them down.

Then, you lay trellis across the canopy, forcing more wide growth. From there, you continue to lollipop your plants up until flower. Visit our blog if you want to learn more about training your plants.

Week 3 Of Veg

After three weeks, your plants are likely ready for full-strength nutrient formulations.

Your plants are starting to look more like adult plants by this point, and you are probably halfway through veg.

Because you are starting to ramp up the ppm's, its probably a good time to talk about nutrient deficiencies and toxicities.

Nutrient Deficiency and Toxicity

If you notice your plants starting to wilt or become dicolored at the tips, it could be from nutrient issues.

We already mentioned how easy it is to overfeed, and when your plant has too much of one nutrient, it may be unable to absorb others. Improper pH dosing can lead to these issues as well.

When your plant experiences nutrient lockout, the tips of your leaves will become brown. Correcting nutrient lockout is usually as simple as flushing the media with plain water.

This will cleanse the medium of the excess nutrient, and allow your plant to start absorbing nutrients the way they should.

On the flip side, nutrient deficiency can present itself as yellowing on the leaves. In this case, correcting the issue is just a matter of feeding the plant more of what it needs.

You can read our definitive guide on plant nutrient deficiencies for more information on which nutrient is giving you grief.

plant nutrient deficiency

Week 4 Of Veg

By this point in your grow, your plants are growing rapidly and you are continuing to train and prune as needed. Around week four is when your plant will start to show its sex.

This is a very exciting time, and its important for you to start watching closely for signs of pre-flowering so you can remove any males you have (if you didn't start from feminized seeds).

You can look closely at growth nodes for indicators. Male plants will show pollen sacs, whereas female plants show little white pistils. At the first sight of pollen sacs, you should remove the guilty plants.

Leaving them around your ladies presents the risk of them pollinating, ruining your crop (unless you want to breed them).

Week 5 Of Veg

We will call this the last week of veg, but you can continue growing your plants under the 18/6 photoperiod as long as you like. They will continue getting bigger and bigger, but at a certain point, you gotta flower them!

This week, do any last pruning and continue feeding your veg nutrient schedule. Some people like to do a flush before flower, but its not necessary. You'll be fine just transitioning right into your flower stage.

If you like this strain you're growing, this is also your last chance to take clones. Some growers take clones during flower, but its definitely not recommended.

The Flowering Stage

The second stage of growing plants indoors is the flowering stage. This is where the fun can really start. Here, you are no longer focusing on any sort of branch development or leafy growth, but instead, flower development.

You will switch the light photoperiod to 12 hours on, 12 hours off. This stimulates the changing of seasons, where the days get shorter and darker in fall.

The flower cycle can take 5 weeks or longer - different strains will take longer to flower than others, so we’ll teach you what to look for to determine when to harvest!

Just like in veg, there are some ways you can boost your bud development. You can stress your plants with additional training techniques, and tweaking the environment.

Week 1 Of Flower

When you make the decision to switch to flower, step one is changing your photoperiod from 18/6 to 12/12. This signals the changing of seasons, and indicates to your plant that its time to start blooming!

You'll also start feeding a bloom-specific nutrient schedule. This new schedule will contain higher concentrations of Phosphorous and lower levels of Nitrogen.

You may have already trellised your plants if you trained them, but if not, now is the time. You'll need to set up trellis over your plants so it can support your branches.

Over the coming weeks, your flowers will get pretty heavy, and you don't want to risk your branches breaking. Indoor growing protects you from heavy winds outdoors, but you still need to provide some support.

You'll probably need water your plants more often than during veg, as your plant has grown and uses water at a much faster rate.

Week 2 Of Flower

After week 2, you won't really be pruning anymore. This is because you just want your plants to focus on flowering.

Pruning at this point can help improve breathability and decrease moisture in the air, preventing that dreaded bud rot.

More importantly, it will allow for greater light penetration. This will promote heavier flowering in areas that would normally be blocked by huge fan leaves.

Weeks 3-6 Of Flower

At this point in your indoor grow, you don't need to do a ton of work. Just keep feeding and watering, watching for issues, and letting nature run its course.

This is around the time you'll start to see buds forming on your plants. At this early stage, they'll just look like little tufts of white hair. They've got a ways to go before you can think about harvesting them.

Over the coming weeks, however, they will continue to bulk up, and fill out your plant.

Week 7 Of Flower

By week 7, your plant should be deep in flower. You're getting close to harvest, so this week you'll cut out all nutrients and just flush your plants. This gives your plants a chance to use up all the nutrients left within them, and it can stress them out a bit. This stress forces more growth out of them.

But, it also eliminates any remaining nutrients in the plant. So, when you consume them after harvest, you aren't consuming any nutrients. This is definitely healthier for you, and it tastes much more natural.

You can use plain RO water, or a flushing agent. These contain special compounds that can grab stray nutrients within the plant easier than plain water.

Week 8 Of Flower

At this point, your flowers are ready to harvest any time now. The best way to determine when your plants are ready for harvest is by looking at the pistils (white hairs on your flower).

When they are all or mostly all white, you still have a couple weeks before harvest. You’ll notice that these pistils undergo a transformation, turning to a milky white, then amber. They’ll begin to darken and curl up.

However, don’t make the mistake of harvesting when you see a few darker, curled up pistils. You need to wait for the majority of them to be amber-colored before they are ready.

Be patient, as harvesting too early will result in lower potency, worse flavor and aroma, and overall disappointment. Give your plants all the time they need to finish developing! Using a microscope will make identifying these trichomes much easier.

How to harvest plants indoors

When you think you have a few days or a week until your plants should be harvesting, cut out all nutrients.

This is known as flushing, and it will force your plants to use up all the nutrients left within their cell walls. This results in a cleaner, better smelling/tasting flower.

Flushing your plants also supercharges bud development, because your plants are stressed out, thinking they are starving. You can use plain water for this, but for the best results, use a flushing agent.

A couple days before the harvest, you can start pulling off big fan leaves, which will save you time while trimming and also speed up the drying process.

Drying your flower indoors

When the time comes to actually harvest, you’ll have to make a decision whether you are going to trim your buds wet or dry. This will affect the steps you take next.

You can read our comparison post on wet vs dry trimming, but if you are growing plants indoors, we recommend trimming dry.

You can easily chop your plants down and hang them in your grow tent to dry. This will take anywhere from 5-14 days.

To determine when your plants are dry enough to trim, take some of the smaller buds and try and snap the stem between your fingers. If it's a clean snap that you can hear and feel, your plants are dry enough to start trimming.

However, if they bend instead of snapping, they need more time. Be patient during the drying process.

Trying to rush through it and get your plants dry fast with excess heat will suck all the aroma and flavor from the flowers, and result in a harsher taste.

Trimming your plants indoors

We will assume you are trimming by hand. You’ll need a good pair of scissors (maybe two), some cleaner, gloves, and a trim bin. Then, just get to work manicuring your flower!

You can remove as little or as much plant matter as you want, but the more you can get the better your flower will look and the better it’ll be.

You can read our full guide on the harvest process here. Once you have all this done, it's time for the final stage of indoor growing - curing.

Curing your flower

The last thing you need to do before you can give your flower a try is let it cure. This is similar to aging wine, and helps the flower finish developing terpenes, flavonoids, and potency.

Trying to comsume your flower right after harvesting it would result in a disappointment in terms of flavor, smell, and effects.

This is the easiest part of indoor growing, but also where so many growers go wrong, and mess up their whole harvest. Simply fill up containers or mason jars ¾ of the way with flower.

For the first two weeks, open the containers a few times a day to let any moisture escape.

This will prevent mold and mildew. After two weeks, you can try some of your flower, but the longer you can cure the better. Some growers will wait 8-12 weeks before they even think about touching their harvest!

You can read our full guide on drying and curing for more information on these important steps.

What comes next?

Once you have some experience growing plants indoors, its just a matter of rinsing and repeating!

You should clean up your grow tent, disinfect hydroponic systems, and throw out old grow media (unless you’re using a reusable one).

Then, if you took some clones from your plants while they vegged, you can get started again. Otherwise, find some new genetics and get back at it!

With a grow under your belt, you may want to try a perpetual growing cycle.

This allows you to harvest plants every 4-6 weeks as opposed to every 8-10. When it comes to indoor growing, one thing is for sure - you won’t get bored.

Looking to learn about outdoor growing next?

Our complete guide will help you understand the outdoor growing calendar, and the differences compared to indoor growing!

Have questions about your grow? We're Here To Help!

Our Northern California based experts can help. We're here to make sure you get what you need to maximize your harvest.


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