10 Essential Supplies for Growing Marijuana Indoors
If you’re new to growing marijuana, it can sound like such a huge and expensive undertaking…
That even though the idea of it interests and intrigues you…
You quickly get overwhelmed by the idea of having to spend into the $1000s, plus the huge amounts of information on the topic…
…and eventually put the idea on hold.
But the truth is:
Growing your own marijuana is far easier and cheaper than you might imagine…
All you need is a few basic supplies and it doesn’t have to cost you more than $600 for an indoor grow, and much less even for an outdoor grow.
It will save you HUGE amounts of money after the initial investment, because you’ll produce more buds than you can smoke…
And they will be so potent and tasty…any herb you had before will pale in comparison.
Which is why in today’s post you will learn:
- The first steps on how to grow your own marijuana;
- The different growing setups, and;
- A list of basic, marijuana growing supplies to get you kickstarted…
First, you have to decide on…
Growing Marijuana Indoors vs Outdoors
While the general consensus is that indoor growing is ‘better’…
The fact of the matter is, whether you should grow in- or outdoors, all depends on your specific circumstances .
Growing indoors takes more skill, maintenance and is less forgiving…
But if you know what you’re doing, the quality of your nugs will be out of this world in terms of:
- Flavor, and;
That doesn’t mean the quality of your yield will be bad in an outdoors grow…
It’s just easier to get those bomb-ass nugs in an indoor grow.
On the flipside:
If you’re going for quantity, an outdoor grow will out-yield an indoor grow by a pretty large margin, with the same number of plants.
In an outdoor grow, your marijuana plants will be larger and full of vigor, producing insane amounts of yield.
So as a general rule of thumb:
- Growing marijuana indoors takes more skill and maintenance, but will produce a higher quality yield ;
- Growing marijuana outdoors takes less skill and maintenance, will produce lowerquality yield , but a much higher yield with the same number of plants and is much cheaper .
But these are not the only differences you should consider…
If you want a year-round harvest and are not living in a tropical climate…you only got 1 choice: growing indoors .
Now, growing indoors does actually bring some extra benefits with it:
- Your marijuana plants will be much less vulnerable to thieves and animals pecking away at your babies. Keep your plants for you and you ONLY .
- It’s much easier to clone your plants. To get yourself free and extra crops of your best plants.
But growing outdoors, brings some additional benefits with it as well:
- It’s much cheaper. All you need are some pots and quality soil.
- You’re growing your plants how Mother Nature intended it to be, which probably has some benefits that are yet unknown.
- If you use a greenhouse, you eliminate many typical outdoor problems like pests and dust pollution.
For most people growing indoors just seems to be the more practical method. Not everyone has a private garden and marijuana thieves are a serious problem.
Next up we have another one of those age-old debates…
Hydroponic Marijuana vs Soil
Is hydroponic growing better, or soil?
Again, there is no ‘better’ method.
But here’s the deal:
When you’re just starting out, I highly recommend you start out with soil, because:
- It’s cheaper;
- Easier to maintain (costs less time), and;
- Much more forgiving than hydroponic growing.
Besides these main benefits growing in soil has a few added benefits like:
- Your marijuana will taste better;
- It’s better suited for small spaces (if you’re short on space);
- It’s more natural, so probably has more hidden benefits (I don’t believe we are smarter than nature).
Reading all these benefits, you might be wondering:
Are there any reasons to choose hydroponic growing over soil?
If you’re prepared to invest your time and learn hydroponic growing properly and accept that maintenance time will be high when you’re learning the ropes of hydroponic growing…
Hydroponic growing actually is an extremely rewarding growing method.
Because it’s easier to control the whole growing process, especially the amount and pace of nutrients, oxygen and CO2 your plants receive…
You’ll receive some benefits over soil:
- Quicker harvest cycles because of reduced vegetation times. Which means more total yield for you;
- Increased yields per grow;
- Easier to get more potent yields;
- Higher density planting leading to increased yields per square foot.
Hydroponic growing essentially is ‘ power growing ’ and is the highest yielding grow method…IF you apply the techniques and maintain your grow PROPERLY.
There are different types of hydroponic growing, which you can learn about here:
Next up is a list of growing supplies you’ll need to get started growing indoors…because let’s be real: indoor growing is what 80% of you will do.
Growing Indoors: 10 Essential Marijuana Growing Supplies
Any marijuana plant needs 4 essential elements to grow:
- Nutrients, and;
What this means is that the growing supplies which provide these 4 elements are absolutely essential .
But to grow marijuana properly indoors, you’ll need a few more extras that support these 4 elements.
Without further due…here’s what you’ll need for a proper indoor growing setup:
- Marijuana Seeds;
- Grow Lights;
- Medium to Grow (Soil, Hydroton, etc.);
- Nutrients and Supplements;
- Pots or Buckets;
- pH and PPM Testing Tools;
- Carbon Filter;
- A Grow Tent.
You might be thinking:
Those are a lot of supplies and the list sounds expensive.
Well, here’s the deal:
If you’re going to grow in soil and going for a 4ft x 4ft space with 1-5 plants, you can easily stay under $650. And your lights will be the main expense here.
In such a grow-setup you can easily yield 4 pounds (1800 grams) of smoke-able high-quality herb.
And if you didn’t know already…
$650 for 4 pounds of quality herb is more than 10 times cheaper than what you would pay at a marijuana dispensary or pharmacy (where you would pay 4 x $1750 = $7000 for the same amount).
Now, if you’re going to grow hydroponically…depending on which system you go for, the cost can add up quickly to over $1000. Because you’ll need more supplies.
But still…even this is 7 times cheaper than buying your marijuana at dispensaries.
Now let’s dive deeper into each item on the list…
1. Marijuana Seeds
Captain obvious speaking:
You can’t grow marijuana without seeds (unless you clone, but I assume that’s not an option for you at this time).
And the quality and strain (genetic make-up) of your seeds will have a MAJOR impact on your results.
How you ensure the quality of your seeds is by buying them from a reputable seedbank with lots of positive and trusted reviews.
But your specific strain is also a topic to think about.
If you’re looking for a specific effect, of course, go for a strain which is known to produce that particular effect…
But with your first grow, you will want an easy grow and a large yield.
Indoors, Indica-heavy strains are easier to grow , flower much faster and will produce a larger yield than Sativa-heavy strains.
Indica-heavy strains are much more compact, which means they need much less space and are more forgiving in case of growing mistakes.
Here are some tried and tested Indica-heavy strains:
- Northern Lights Autoflower Fem.–(CropKingSeeds – Worldwide / Seedsman – UK)
- Purple Kush Feminized–(CropKingSeeds – Worldwide / Seedsman – UK)
Now, if you really want to grow Sativa-heavy strains, I recommend you take a hybrid. Because 100% Sativa strains are really not that well suited for compact indoor growing setups.
Here are some tried and tested Sativa-heavy strains, that are actually pretty well suited for indoor growing:
- White Widow Fem.–(CropKingSeeds – Worldwide / Seedsman – UK)
- Sour Diesel Feminized–(CropKingSeeds – Worldwide / Seedsman – UK)
Next up we have your piece that will have to replace the sun…
2. Grow Lights
Since you’re growing indoors…
You’re going to have to replace sunlight, which is by no means an easy task.
And most beginning growers are extremely scared of the electric costs of a grow light…thinking it will quickly add up into the hundreds.
While this is true for certain types of grow lights, covering large spaces…
A high-quality LED light will hardly add something to your electric bill.
- Spider Farmer SF – (EpicLEDGrowLight > 3% off coupon code: HERBONAUT/ Amazon)
There are many more options when going for a LED light and I cover the 5 best of them here:
Now, the initial investment is higher if you go for a LED light though.
The other option you have is an HPS light, which is a cheaper initial investment but will be more expensive in terms of electricity and replacement costs (you’ll need to replace it every 1-6 months, depending on the quality of your HPS light).
Do realize that ventilation will be more important with an HPS light because it generates way more heat than a LED light…so don’t cut corners when buying an exhaust fan if you decide to go for an HPS light.
To operate, an HPS light will need a ballast for power and hood/reflector which reflects all the light to your plants.
If you’re just starting out, an easy option is to get a full HPS grow light kit which includes both the ballast and the hood.
- Apollo Horticulture 400 Watt Grow Light Digital– (Amazon)
A general rule of thumb with grow lights is to get 50 watts per square foot.
Let’s say you get a 4×4 tent. Then you will need 16×50 = 800 watts.
You have 2 options here:
- Get 1x 1000W light, or;
- Get 2x 400W lights.
Getting 2x 400W lights will be better for your plants because you can position them more easily and optimize the spread of your light…
But, if you’re going for an HPS light at least, getting 1x 1000W will be cheaper.
If you buy pre-made lights you won’t need any hanging ropes.
But if you go for a DIY light, you will definitely need a way to hang your lights.
The most secure and flexible (flexible as in easily adjustable height) to hang your lights is with:
- Rope Ratchets– (Amazon)
Next up we have your…
3. Growing Medium
Since plants can’t float around in the air…
You also need a growing medium to support your plants.
What type of growing medium you use, is fully dependent on whether you’re growing in soil vs hydroponics .
If you choose to grow in soil, you’ll need (surprise, surprise) soil as a growing medium.
An easy way to get started is with pre-made soil which is ready for use straight out of the bag .
- FoxFarm Ocean Forest– (Amazon / Grower’s House)
If you choose a hydroponic system, you’ll need an inert medium like hydroton or lava-rock.
- Hydroton– (Amazon)
Another important to note here is that soil actually is a supplier of nutrients and an inert medium like pebbles isn’t, it’s just there to hold your plant in place.
And that’s why the nutrients and feeding schedule of soil is different than a hydroponic system…
As you will learn when we talk about the building blocks of your marijuana plants…
4. Nutrients and Supplements
Nutrients When Growing in Soil
Just like every living organism, your marijuana plants need nutrients to grow.
Without nutrients, no plants. It’s that easy really.
But what kind of nutrients you need depends on:
- Whether you’re growing hydroponically or with soil, and;
- If you’re growing in soil: whether you’re growing in organic super-soil, organic high-quality soil or just normal soil (normal soil is not recommended).
If you’re growing in organic super- or high-quality-soil, you might need a small amount of nutrients to adjust nutrient-strength levels or work out a deficit after the first few weeks when you’re plants are deeper into their vegetative stage and/or start to enter their flowering stage…
But most of the nutrients will already be in your soil, and you might even overfeed your plants by adding extra nutrients.
Still it can be helpful to add small amounts of organic nutrients to your plants once they get into their flowering stage.
Classic example soil-based organic nutrients:
- Fox Farm Big Bloom Fertilizer– (Amazon / Grower’s House)
Now, if you’re growing in regular soil, you’ll definitely need a good set of quality nutrients.
But I don’t recommend growing in regular soil as it’s just much easier and more natural to grow in organic super-soil packed with nutrients.
Nutrients When Growing in a Hydroponic System
When you’re growing hydroponically, it’s your water that provides the nutrients.
And since water naturally doesn’t have the nutrients your marijuana plants need…
You will definitely need nutrients.
When you mix water with nutrients, that’s what’s called your nutrient solution. And you will feed your plants with your nutrient solution.
Classic example nutrients for hydroponic systems (you need to combine all 3):
- Jacks Hydroponic 5-12-26 Jack’s Professional– (Amazon)
- Jacks Calcium Nitrate 15.5% Nitrogen 18% Calcium – (Amazon)
- Pennington Epsom Salt– (Amazon)
Remember that your plants will need a different nutrient profile per growth stage (vegetation vs flowering). Check out this page for a guide on nutrient profiles for marijuana when growing hydroponically.
Next up we have…
5. Pots & Buckets
Since we’re growing indoors and can’t make use of the ground…
We’ll need something to put our growing medium and plants in like pots, buckets or containers.
Now, if you’re growing in soil smart pots are great to start with.
Because they really do protect you from some common mistakes like:
- Bad soil;
- No root binding;
- Root rot.
They are a bit more expensive than regular pots but well worth the price.
The size of your pots depends on your grow space, but if you want decent sized plants go for at least 5-gallon pots.
- Smart Pots 5 Gallons– (Amazon / Grower’s House)
If you’re growing hydroponically you don’t need fancy pots.
Usually, you’ll use buckets.
And if you get a pre-made hydroponic system (which is highly recommended if you’re a complete beginner to hydroponic growing), the buckets usually are included with your system.
Next up we have the lungs and cooling mechanism of your grow environment…
If you’re going to replicate nature…
Your plants are going to need a steady flow of fresh air with CO2.
And the best way to provide them with fresh CO2-rich air is through proper ventilation.
But there’s another very important reason why you want proper ventilation…
High temperatures can quickly destroy your crop. And proper ventilation keeps the temperature in your grow room / grow tent in check.
Proper ventilation consists of 3 parts:
- Active air exhaustion;
- Passive or active air intake, and;
- Air movement.
For proper ventilation, you need all 3 of these elements to be present.
Depending on your budget you have many options to buy ventilation supplies…
But when you’re starting out, there are 4 essential things to keep in mind:
- Know the volume of your grow area / grow tent (4x4x6 ft. = 105.6 cubic ft.);
- Get a fan which has AT LEAST a Cubic Feet per Minute (CFM) rating that is equal to the volume of your grow area / grow tent;
- If you’re going to get a carbon filter (to filter unwanted smells) add 25% to that number;
- Get a centrifugal inline fan;
- An exhaust fan is more important than an intake fan.
For beginners, I recommend using a passive intake (a hole or 2 on the opposite end of your exhaust fan in your grow tent) and an inline exhaust fan that satisfies the above requirements.
If you’re going for an inline intake fan, make sure to get a fan that’s 10-15% less powerful than your exhaust fan. This is because you want to keep negative pressure in your grow space. Negative air pressure ensures all the air passes through your carbon filter.
- Hurricane Inline Fan 4 in 171 CFM – (Amazon / Grower’s House)
Here’s how you hang your fan:
- Rope Ratchets– (Amazon)
Every plant has an optimal temperature level at which the maximum level of photosynthesis takes place.
But with marijuana it’s even a bit more complicated:
Different strains have different optimal temperature levels at which they produce the most potent buds.
To create the perfect environment for your particular strain it’s important you keep the temperature in your grow room / grow tent at this optimal level.
And since, unless you have some special powers, you have no clue whether the temperature in your grow area is at this optimal level…
You really need a thermometer.
Now, a basic thermometer is cheap, and all you need when starting out.
- AcuRite Indoor Humidity Monitor – (Amazon)
Next up are the essential tool-kits…
8. pH and PPM Testing Tools
Marijuana plants not only have an optimal temperature to grow…
It’s ESSENTIAL that you keep the pH levels (acidity or alkalinity) of your soil or nutrient solution (when growing hydroponically), at an optimal level as well.
Because pH affects:
- Nutrient availability;
- Nutrient leaching;
- The bacteria in your soil, and;
- Your soil structure.
Get your pH wrong and your plants will suffer severe malnutrition and it will be very hard to save a crop of prolonged cases of malnutrition.
Either the potency and taste of your buds will SUCK or your plants will flat out die.
The optimal pH-levels:
- Hydroponic grow: pH 5.5-6.5 or game over;
- Soil-based grow: pH 6.5-6.8.
It literally is a matter of life-and-death for your plants…
Luckily there’s a very handy tool that will help you keep the pH in check: a pH-meter.
Now, soil and water (hydroponic growing) have different pH meters. So don’t buy a pH-meter before you’ve decided on soil vs hydro.
Classic example pH-meter SOIL :
- Dr.meter 3-in-1 PH Acidity Tester – (Amazon / Grower’s House)
Realize that when growing hydroponically it’s important you get a quality pH meter that works in water. Because your pH will be more susceptible to fluctuations than when growing in soil. Plus, as you’ll read below…when you’re growing hydroponically you want a quality PPM- / EC-meter as well. Which means it’s best to immediately get a combo-meter (pH and PPM).
A high-quality pH- and PPM- / EC-meter isn’t cheap and one of the reasons why growing hydroponically is quite a bit more expensive than growing in soil.
Classic example pH- and PPM- / EC-meter HYDRO:
- Bluelab Combo Meter – (Amazon / Grower’s House)
It’s also important you actually have an easy way to adjust your pH when it’s off.
Again, this is especially true if you’re growing in a hydroponic system because of the potential swings in pH values.
Soil actually acts as a natural buffer, as long as you feed your plants with a slightly alkaline nutrient solution (above 7 pH).
You can easily do this with a pH control kit:
- General Hydroponics pH Control Kit – (Amazon)
Then the EC/PPM/TDS Meter…
The question is: do you really need one?
If you grow in the soil it’s useful but not necessary.
But if you’re growing hydroponically, you will definitely need one.
Your nutrient-strength-level is less variable when growing in soil than when growing hydroponically.
When growing hydroponically, your plant’s roots are directly exposed to your nutrient-solution and small fluctuations in strength-levels can have a huge impact on the growth of your plants.
Combine this with the fact that your marijuana plants need different nutrient strength-levels at different stages in their growth process…
And you’ll quickly understand why a PPM-meter is important when growing hydroponically.
If you give your plants fewer nutrients than they need, you’ll severely stunt their growth. And if you give them more nutrients than they need, you risk burning your plants.
With a PPM-meter, you can actually measure the nutrient-strength of your soil or nutrient solution, and keep the nutrient-strength at the optimal level.
- Bluelab Combo Meter (pH and PPM) – (Amazon)
For a chart with a general overview of recommended nutrient-strengths per growth stage, click here.
9. Carbon Filter
Even though I absolutely LOVE the smell of weed…
I don’t really want my whole house smelling of marijuana.
But when you’re growing indoors, this really can be a problem.
Luckily, there’s an easy way to eliminate 95% of the smell: a carbon filter.
So although this is not an essential tool to grow your marijuana, it is essential if you care about odor.
In the ventilation chapter, you learned that you should get an exhaust fan that has a CFM rating that’s at least equal to the volume of your grow area / grow tent.
Your filter should be the same or close to the CFM rating of your exhaust fan.
- Phresh Filter– (Amazon / Grower’s House)
Do realize that choosing an isolated spot for your grow is much more effective than any filter.
10. Grow Tent
Although a grow tent isn’t absolutely essential…
If you’re growing indoors a good grow tent is highly advisable.
The other option you have is to grow in a room or closet.
And while it might seem unnecessary to get a grow tent, if you have a spare room or closet…
A grow tent will ease and support your growth process in many ways:
- Easier to control pests;
- Light reflection (helps your plants grow stronger and faster);
- Lightproof environment (prevents stress on your plants);
- Isolation (of smell and infections);
- Easy temperature and humidity control (prevents stress on your plants).
With a properly setup room or closet, you’ll have exactly the same benefits…
But if you’re a beginner, getting a grow tent will save you loads of time and effort.
Besides a quality grow tent is easy to move, very affordable, and will last you at least a couple of years.
These are the best grow tents I recommend:
- Apollo Horticulture Grow Tent – (Amazon)
You now know which supplies you need for a basic indoor growing setup.
But this is only half of the story.
Now you need to know how to set up your growing space…
And how to actually grow your marijuana.
Which is what we will cover in the next post:
Learn what supplies you need to master your first grow, get the best setups for beginners and amazing tips to maximize your yield!
An intro to indoor cannabis cultivation
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- What are the basics of growing weed?
- How to start growing weed
- What Is the best way to grow marijuana indoors?
- Cannabis feeding systems
- Setting up your grow: choosing a space
- Creating the ideal environment: lighting
- Creating the ideal environment
- Tips for success
- Frequently asked questions
What are the basics of growing weed?
Indoor cannabis cultivation is a rewarding endeavor that basically can be done in any climate. Growing pot takes attention to detail and the right equipment, time, and money, but the benefits reaped from growing your own weed are more than worth the time and expense. Not only is the practice of gardening itself therapeutic, it also lends a connection to the plants that cannot be experienced outside of a hands-on approach. Having trained and grown out a favorite cultivar to fruition is one of life’s great joys for a marijuana enthusiast.
Indoor cultivation provides many benefits compared to outdoor cultivation, including control, reproducibility, and risk mitigation — not to mention location, location, location. The goal is to artificially create the ideal environment for your plants at all growth stages. This is achieved through precise lighting, temperature, humidity, carbon dioxide content, and air movement within each indoor growing space.
Ultimately, the costs of equipment and recurring utility bills are more expensive than in outdoor and greenhouse settings. However, specialized indoor cultivation equipment allows cultivators to achieve multiple harvests per year and a more reproducible product. If you’re detail-oriented and technologically inclined, indoor gardening is a fun and rewarding pastime, or could even be a full-time job.
How to start growing weed
To set up an indoor garden, you will need equipment to help create a stable environment that mimics the necessary periods of light and darkness to grow plants through the flowering stage. This includes horticultural lighting, fans to recreate a gentle breeze, dehumidifiers to maintain the proper humidity, HVAC (heating, ventilation, and air conditioning), and all the basic supplies that a plant needs to survive, from water to grow media to nutrients.
Planning, designing, and implementing an indoor garden can seem daunting, but having a firm understanding of the basics goes a long way in helping a new indoor grower get started on the path to a healthy and bountiful harvest.
What Is the best way to grow marijuana indoors?
The first step in creating a proper indoor growing environment is to decide on the medium and irrigation methods you’ll be using to supply your plants with the proper nutrients throughout their growth cycle. The medium is a shelter for your plants’ roots that retains moisture. The irrigation method is the way you deliver nutrients to the plants.
Unlike outdoor cultivation — where you almost always use soil to grow your plants — growing indoors offers several different options for growing systems and media. Some media are easier to work with than others, while some are a little trickier, but offer more control over the finer details. Different media retain moisture at different rates, which in turn determines how often plants need to be watered. Some media harbor beneficial microbes that can help roots absorb nutrients better.
The two main options for an indoor garden are soil and hydroponic media. Consider the following:
Soil is a great choice for beginners. It can be much more forgiving and requires less precision when watering and feeding plants. Less-frequent watering and a stable pH foundation can drastically increase the likelihood of a successful first harvest. Soil also contains beneficial microbes and nutrients that help keep plants healthy, though it also creates favorable conditions for pests, mold, and mildew to spread. Working with soil and hand-watering plants can also be messy, but it will allow you to get familiar with the pace in which your plants consume water and nutrients.
Soil can be much more forgiving and requires less precision when watering and feeding plants additional nutrients. Photo by: Gina Coleman/Weedmaps
Hydroponic media are viable indoor alternatives to soil, but they’re considered more advanced because they bring with them a set of challenges that may prove difficult for beginners. Then again, if going hydroponic is in your plans, it’s best to learn the method from the beginning.
Hydroponics is a blanket term for the growing of plants in a nutrient solution, with or without an inert medium to provide physical root support. Media such as fused basalt rock and chalk (known as rockwool), coconut fiber (coco coir), and clay pellets (hydroton) can drastically improve nutrient delivery. With a plant’s roots system exposed, hydroponically grown cannabis can grow faster and more efficiently, requiring less water and fewer nutrients but also requiring monitoring systems to ensure a stable pH.
Rockwool , also known as mineral wool, is one of the most common forms of hydroponic media for the beginning stage of a plant’s life. Rockwool is an inert substance, and its composition of mineral or rock fibers provides a relatively sterile environment with a unique capacity to hold water. Rockwool will quickly expose any watering or feeding mistakes. Missing even one day of watering could be detrimental when using rockwool, especially for tender young plants.
Coco Coir is the fibrous material found on and in coconut shells. As a byproduct of the coconut industry, it is favored by growers as a sustainable and renewable medium. Coco coir is an inert medium with a neutral pH that does not provide or maintain any nutrients. These qualities are great for growers who know how to appropriately adjust pH, allowing for quick pH and nutrient changes. There may be a learning curve, but if you’re numerically inclined, it’s not too hard to get a grip on the process. Coco coir can be used either by itself or added to soil or hydroton for improved drainage and growth capability.
Coco Coir is the fibrous material found on and in coconut shells. Photo by: Gina Coleman/Weedmaps
Hydroton is a lightweight expanded clay aggregate composed of porous clay pebbles that can be used alone in a hydroponic system or blended with soil or other soilless mediums. Hydroton does not retain water to the extent of coco coir or rockwool, but it does provide plant roots with equal levels of oxygen. Like rockwool, the biggest issue is that it can dry out very quickly, so you have to be extra careful to keep it hydrated, especially when used on its own.
Other common soilless mediums used by hydroponic growers include perlite, vermiculite, coarse sand, and gravel. Advanced growers frequently mix these media in custom quantities to create blends that suit their specific growing style and environment.
Cannabis feeding systems
Feeding your plant is the process of giving it the chemicals and compounds that it needs to grow out its leaves, roots, and ultimately produce the heavy, trichome-covered flower clusters called colas. There are two main types of feeding systems: drain-to-waste and recirculating.
A drain-to-waste system applies fresh nutrient solutions to the grow medium every time the plant is fed. Any nutrients that drain through the medium are then disposed of and not reused.
A recirculating system collects the nutrients and water that are used, replenishes them, but with a smaller amount of fresh nutrients, then reapplies the solution to the plants the next time the plant is fed. A grower will check the solution’s pH before and after adjusting the nutrients.
When using soil as your primary medium, drain-to-waste is the only possibility. In soilless hydroponic systems, it is up to the growers’ preferences. Most hydroponic growers will opt to maintain a drain-to-waste system, because it affords them full control over the application of nutrients. Recirculating systems are typically reserved for the most advanced and efficient cultivators.
Top feed drain-to-waste systems can be as simple as putting your plants in a soilless medium and watering them from the top of the container, either with a drip system or by hand.
Ebb and flow systems, also known as flood and drain systems, are a popular type of recirculating system that uses a pump to bring water and nutrients from a reservoir into a flood tray where the plants are positioned in their grow medium. The nutrient solution floods the tray and gets absorbed by the roots and medium before slowly draining back into the reservoir. This process repeats itself on a timer to ensure that plants are properly hydrated.
Nutrient Film Technique (NFT) is another recirculating system in which plants are suspended by net baskets or neoprene collars that run along a trough. A thin film of water and nutrients continually circulates through the bottom of the trough, providing food to the tips of the roots, while leaving a majority of the root mass exposed to air.
Deep Water Culture (DWC) is a modular bucket system that suspends the plant’s main stem in a net basket while the roots are completely immersed in a highly oxygenated nutrient solution. An air pump supplies the oxygen to the nutrient solution which circulates through 3-5 gallon, or 11.4-18.9 liter, pots. DWC buckets can be configured to run in a stand-alone drain-to-waste system, or all of the buckets can be connected together to run in a recirculating manner.
Aeroponics are hydroponic systems in which the roots are suspended in air and lightly misted with a nutrient solution on regularly timed intervals. This method can achieve faster growth rates while using less water and nutrients than other hydroponic systems, though this is considered of the most advanced methods of growing hydroponically.
Setting up your grow: choosing a space
Before you purchase any equipment, it is important to understand the possible limitations of an indoor garden. Consider the height of the ceiling, how much insulation your space offers, and your ease of access to electricity and water. Some local jurisdictions may also ask that indoor gardens mitigate odors during the flowering phase.
If you’re a beginner, prefabricated grow tents are a great option, as they allow for minimal wear and tear on your property. Instead of renovating or building a new room, grow tents can be set up and taken down in a matter of minutes while also providing a clean, reflective, and enclosed environment for your plants to grow. As a general rule, your ceiling height should be at least a height of 8 feet, or about 2.4 meters; this is the typical height of a tent. Check your prospective tent’s measurements before committing to the purchase.
Grow tents also make it easier for home growers to maintain two separate environments: one for vegetative growth, and the other for flowering. This allows you to keep a perpetual harvest going by propagating and growing young plants in one tent and flowering another set of plants in the other tent. Maintaining a balanced rotation like this can result in maximized harvests year over year.
Whether you are growing two or 30 plants in your house, grow equipment requires a significant amount of electricity, primarily from your lighting and air conditioning units. Make sure that all electrical equipment is installed by a trained professional to reduce the likelihood of an electrical fire. You don’t need to be an electrician to design an indoor grow, but having a basic understanding of watts, volts, and amps is essential. The equation below can be used to determine whether your property has the minimum amount of power for an indoor garden:
Always make a list of the power requirements for each piece of equipment and make sure your electrical panels can support the electrical load before you make any big equipment purchases.
Water quality is another key aspect of indoor gardening. It’s important to determine water acidity and general mineral content prior to planting. Checking the pH, the acidity or alkalinity of the water, is easy to do with a handheld water quality meter. The same device can be used to check the total mineral or chemical content of your water as well. Knowing these things will help you determine the correct amount of nutrients to feed your plants or if fresh water needs to be introduced.
Most local jurisdictions require you mitigate the odor from your plants to avoid disturbing your neighbors. Activated charcoal filters absorb plant odor in your grow area. Adding a charcoal filter to your HVAC system or placing one within your grow space is a great way to drastically reduce the odor. The size of the filter is largely dependent on the size of your grow. Make sure filters are sized and installed correctly. Keep track of the life of the filter, as their effectiveness diminishes over time.
Even when growing cannabis legally, it’s a good idea to minimize your public visibility as a grower and take some mild to moderate precautions. Simple steps, such as not geotagging your location when you post grow pictures or hiding the glare from your grow lights when you run them at night, can go a long way in keeping your prized indoor garden secure.
Creating the ideal environment: lighting
Choosing the right horticultural lighting for your indoor grow can mean the difference between success and failure. Correct lighting is crucial, as it drives photosynthesis. In other words, your plants will not grow properly without proper lighting. The duration of your lighting controls the photoperiod, or the times in which a grow is exposed to light. During the vegetative growth phase, plants need a minimum of 16 hours of light. The most common schedule during this phase is 18 hours of light and six hours of darkness. To initiate flowering, plants need a shorter day, with 12 hours of light and 12 hours of darkness.
Correct lighting is crucial, as it drives photosynthesis. In other words, your plants will not grow properly without proper lighting. Photo by: Gina Coleman/Weedmaps
The intensity of light and its placement within your grow space are important aspects to consider when choosing what kind of light to grow with. Low light levels will slow photosynthesis, delay growth, and result in poor yields. If your light is too far away the plant will not receive enough of it and will grow spindly. If your light is too close it can damage the plant and ruin your colas.
There are several different types of grow lights that serve different purposes, each with their own sets of pros and cons.
Fluorescent lights are affordable and use minimal wattage to produce a low-intensity light. They are available in strips or larger arrays of multiple bulbs, and are most commonly used during the germination and propagation of seeds and clones. They should not be used during the flowering phase.
Metal-halide (MH) lights are a type of high-intensity discharge (HID) lights that work by igniting gas in a tube with a spark of electricity. Metal-halide bulbs emit a spectrum of light that is most beneficial during the vegetative phase. They emit more usable light for a plant than a fluorescent bulb does, but tend to cost substantially more.
High-pressure sodium (HPS) bulbs are highly efficient HID lights that produce a very effective spectrum of light to promote growth during the flowering phase. Most HPS bulbs are double-ended and can last 10,000 hours without losing efficiency. While these lights are the workhorses of most grow rooms today, they produce a significant amount of heat that needs to be removed, increasing air conditioning requirements.
Light-emitting diode (LED) lights are another form of high-intensity lighting that have been growing in popularity as their technology has advanced. LED lights produce a spectrum suited for all phases of plant life. They typically cost more than other grow lights, but they last much longer, are more energy efficient, and give off a lot less heat than HID lighting.
Creating the ideal environment
When it comes to cultivating cannabis indoors, you need to be sure to provide your plant with the optimal temperature, humidity, air circulation, CO2, and nutrients.
Temperature and Humidity
Maintaining the ideal temperature and humidity at all times is crucial to the health of your plants. Some plant varieties prefer hot and humid climates, while others like it cool and dry. Keeping them alive and healthy means controlling the temperature and humidity when the lights are on or off.
Air conditioning (AC) and humidification systems are used to control the temperature and relative humidity of an indoor grow room. The size of each unit is based on the amount of heat the lights and other equipment produce in relation to the size of the space. In an open grow room, intake and exhaust fans are used to constantly exchange the air within the room to maintain a consistent temperature. In sealed rooms, mini-split AC systems are used because they circulate the air in the room without bringing in fresh air.
AC systems maintain temperature and also dehumidify rooms. Fluctuations in humidity can affect plant health and should be controlled using a dehumidifier or humidifier, depending on conditions.
Advanced growers use digital environmental controls to monitor all equipment responsible for maintaining a stable environment (i.e., fans, AC, dehumidifiers, sensors, thermostats, etc.). These environmental controls can be worth the hefty price tag for the peace of mind they provide.
With lighting, AC, and other environmental controls in place, indoor cannabis plants will require large amounts of fertilizer or nutrients throughout their lifespans. Hydroponic systems lack the base nutrients that occur within soil; that leaves it up to you, the grower, to feed their plants with nutrient concentrations — the exact formula of which depends upon plant variety and phase of cultivation. With hydroponics, salt-based nutrients typically come in the form of a concentrated liquid or dry soluble powder that can be mixed with water.
As a cannabis plant develops, its nutrient needs change. That’s why different nutrient lines are available for different growth phases. Most nutrient lines come with recommended feeding charts. If you’re just starting out, be sure to get to know your nutrients and their ratios.
Carbon dioxide supplementation
Controlling the amount of available carbon dioxide (CO2) in your garden is another aspect of growing marijuana at home . During photosynthesis, CO2 converts into sugar, which the plant uses as energy for growing its vegetation and, ultimately, its seeds or flowers. Adding CO2 to your indoor garden can drastically improve your yields. While the atmosphere naturally has an average CO2 concentration of around 400 parts per million (PPM), most indoor growers try to maintain a range of 800 to 2,000 PPM, depending on the plants’ growth stage. Levels above 2,000 PPM can damage plants, and anything above 3,000 PPM can be dangerous to humans.
The amount of CO2 you supplement your garden with depends on how much light your plants are receiving, the growth phase they are in, and their overall size. CO2 should only be used during the “daylight” period, as plants are unable to utilize CO2 at night or in the dark. Sealed grow rooms are ideal when supplementing CO2, as open rooms tend to exhaust the CO2 more quickly than the plants can use it.
CO2 can be supplemented into an indoor garden using compressed gas tanks or generators. Using compressed CO2 tanks is the most common method because they’re readily available, easy to set up, and do not add any extra heat to your room the way a CO2 generator does.
Air movement is the least expensive component of creating an ideal environment for your plants. Even a gentle breeze can help keep pests and microbes from landing on your plants, move oxygen and carbon dioxide around the leaves, and create a uniform environment throughout your room. One of the easiest ways to maintain sufficient air circulation is by hanging oscillating fans on the walls or ceiling/grow tent corners and placing a small box fan on the floor. The goal with air circulation should be to mimic a light breeze and avoid powerful gusts that may harm your plants.
Tips for success
The health of your garden is completely dependent upon the environment you create and the equipment you select. It is easy to buy a new line of nutrients, but much more difficult to replace an undersized air conditioner. Careful planning prior to your grow will go a long way in saving you from expensive mishaps.
Cleanliness in an indoor garden cannot be overstated. Clean your entire grow room before your first grow cycle and after every harvest. The walls, floors, trays, irrigation lines, reservoirs, lights, and fans should be cleaned using a three to five percent (3%-5%) hydrogen peroxide solution, an efficient sterilizing agent that leaves no dangerous or toxic residues behind. Be careful what you bring into your grow room. Pets, dirty clothes, and contaminated clones can introduce unwanted pests and diseases.
Maintaining a grow journal and logging all major aspects of your grow is one of the cheapest, easiest things you can do to become a better grower. Logging daily temperatures along with water and feeding amounts will help you pinpoint problems, and may give you something to show other growers who can help you resolve issues, increase your yields, and save a troubled crop.
Remember, not everyone was born with a green thumb or an affinity for setting up and maintaining equipment. But with practice, passion, and an attention to detail, you can ready yourself for an amazing growing experience that has the potential to change your views of and interaction with cannabis for good.
Frequently asked questions
Should you grow cannabis with distilled water or reverse osmosis water?
Distilled and reverse osmosis water are fairly comparable. It’s the process of distilling that differs from the reverse osmosis process. Distilled water has been boiled to a vapor and cooled back into liquid to filter out contaminants. Reverse osmosis (RO) filters pressure water through a filtration membrane and produce wastewater as a byproduct. They’re generally better than distillers at removing volatile chemicals such as chloramines.
RO filters can remove 95% or more of contaminants, and typically increase in efficiency when pre-filters are placed before them in a filtration system. Carbon or sediment filters remove chlorine and chloramines as well as larger solids such as sediment and dirt. Water softeners exchange calcium and magnesium for sodium chloride so it can be purified and softened through the RO filter.
There are big differences when you grow cannabis indoor versus outdoor. Learn everything you need to know about growing weed indoors.