How To Build A DIY Stealth Grow Box

When stealth is the name of the game, building your own secret garden in the privacy of your own home can give you the peace of mind you always wanted. In this article, I explain all you need to know about stealth boxes, including soundproofing, hydroponic, lighting options, homemade stealth box ideas, how to build and set up your stealth box, and my final thoughts and tips.

What does a stealth grow box need?

Not every grower has the freedom to legally grow their personal head stash. Those who live close to neighbors need to be especially careful. In certain parts of the world, growing cannabis for any reason is deemed a criminal offense with potentially years of ongoing court cases. 

For that reason, stealth grow boxes should be silent, discreet, and small enough to hide away in a bedroom. Before you start designing and building your stealth grow box, there are many factors to consider. You’ll plan for noise control, odor control, lighting options, and reflective material. 

Key requirements for a stealth grow box:

• There should be minimal noise.
• Proper odor control using a carbon-activated filter.
• All points are well sealed to prevent light breaks.
• A quiet entry point each time you open.
• Ducting should be airtight and well-fitted.
• A fan (inside) that is, ideally, oscillating.
• Plugs and wires should be neatly set up

How much does a stealth grow box yield?

How long is a piece of string? This all depends on many factors. First-time growers should not concern themselves with yield. Instead, they should become fully consumed in the experience of growing from cannabis seed to harvesting! However, below are some different ways to ensure a good quality harvest and get the most out of your stealth grow box.

Autoflowering cannabis seeds – Autos are small-sized plants that do not stretch much once flowered. I have had loads of success when starting out growing feminized autoflowering seeds indoors in small-sized and compact spaces. 

Hydroponic systems – If you need to rely on big yields, short vegetative times, and an easy way of life, then hydroponic systems can do the job. Deep water culture, NFT systems, and aeroponic are all designed to produce heavy harvests in small spaces. NFT systems are my personal favorite for stealth grow boxes. 

Want to learn how to yield the most from your indoor grow? Check out our marijuana grow bible for ultimate tips on every grow!

Stealth grow boxes for sale

Grow boxes come in various styles, types, brands, and levels of quality. For advice on which type or brand to buy, I suggest looking at our  best grow box review. 

Cheapest stealth grow box

Personally, I prefer ordering grow tents that can be set up within an hour of arrival based on practicality and the fact that the complete tent will be airtight and lightproof. However, converting a spare cupboard is fun, easy to do, and a great stepping stone in the world of indoor cultivation.

Shop Indoor Seeds

• Indoor-thriving plants
• For windowsill or under lamps
• Feminized and autoflowers seeds

Homemade stealth grow box ideas

Growing cannabis is a fun hobby for most. If you want to take that hobby to another level, why not consider other DIY home inventions? Below are a few ideas to consider when designing your stealth grow box.

Stealth grow cabinets

T5 strip lights or CFLs are your best bet if you grow cannabis in a cabinet. I would also recommend using autos or indica genetics. 

Speaker grow box

This option is another miniature-sized stealth grow box that is more for a hobby. Plants inside will not have much room to grow and will only produce little buds; however, it’s still a fun project. 

PC tower grow box

This tiny option is truly stealthy. Plants grow inside the tower,  powered by PC computer fans. Amazingly, plants can grow on such a small scale! I have seen these in the past, but never in person. 

Stealth hydroponic grow box

This option is easily your best bet on learning about pH, E.C., and harvesting a good amount of high-grade bud. Hydroponics and aquaponics are known for returning big yields in short spaces. 

Stealth grow tents

Grow tents are my go-to option. They are easy to set up and let you open the side vents or use an intake and outtake fan. This ensures a fresh air flow entering and exiting the tent (negative drag or suction effect).

Stealth closet grow

Closet grows are popular; in fact, it was my first indoor experience. Clueless but ambitious, I removed all the clothes and set up CFL grow lights. Closet grows can work; just ensure you seal all gaps and make it as airtight as possible.

Soundproofing your indoor garden

There is nothing worse than plugging in your extractor, fans, grow lights, and, in some cases, air pumps and listening to the aggressively whirring sounds. This may be fine for those in the countryside or far away from neighbors; however, loud noise and reverberation through the floors and walls may quickly annoy neighbors.

Here are some ways to soundproof your stealth grow box, depending on your budget and grow space. 

• Passive cooling grow lights
• Acoustic ducting
• Silencers
• Plug dimmers
• Using T.T fans
• Acoustic wooden boxes
• Silent operating hydroponics

For more on soundproofing your grow room or tent, read my article “How to Soundproof Your Grow.” 

Odor control

Now that we have covered soundproofing, the next thing to consider is odor control. There is no point in having a stealth grow box if it fails in design due to poor odor control. The best way to control odor is with a carbon filter. It scrubs air using carbon before exhausting it. 

Advice when using carbon filters

• Use ducting tape to produce an airtight fit over the ducting.
• Replace your carbon filter after every two harvests.
• Remember: the extractor is responsible for how much fresh air is produced.
• Do not grow cannabis indoors without a carbon filter.

Heat Management

The amount of heat generated in your stealth grow box will come down to the heat from the grow light, ballasts, and air pumps (DWC / RDWC). Cannabis prefers a temperature of 75 degrees Fahrenheit (24 ℃) to grow the healthiest and most productive plants. 

The efficiency of your ventilation will depend on how much air the extractor can exhaust. Once plants experience temperatures exceeding 75 degrees Fahrenheit (24 ℃), they will start exhibiting signs of heat stress. 

Tips for effective heat management

• HPS or metal halide lights can burn extremely hot inside small spaces.
• Fans inside stealth grow boxes can help keep the temperatures cooler.
• HID ballasts can also heat up and become excessively hot to touch.
• High temperatures and poor extraction will lead to higher humidity levels.
• It may be best to create as much space between the light and the plants.
• LED is often the best option for low-temperature lighting in small spaces. 

A Complete Grow Kit

• Everything you need to grow!
• 20 feminized seeds
• Marijuana Fertilizer
• Plant Protector

Lighting options

Finding the ideal grow light to fit your stealth grow box may limit your resources. However, there are plenty of good, not overly expensive options. 

Compact Fluorescent (CFL)

CFLs are a popular option for growing cannabis indoors. I personally loved them. You can use the blue spectrum light for the vegetative state and the red light for flowering. Growing high-grade weed is possible with CFLs, but don’t hold your breath on the yield side. 

T5 strip lights

This modern upgrade to the clunky CFL lights uses a reflector and hanging gear. T5 strip lights are much more efficient and produce an even spectrum of light across the canopy. Typically used for clones, seedlings, and mother plants, T5 lights are a wonderful starting point for a first-time bedroom grower and don’t use much electricity or generate much heat.

LED lights

The evolution of the indoor grow light has shifted so much in the past decade, with many growers investing in LED lights. Now, like anything in life, there is always a cheaper version. However, do not waste time with Chinese-made LED or old-fashioned designs with low PAR ratings. 

250-400w HID

If your extraction is working well, you should be able to install a 250w or 400w HID grow light. What I mean by this is using either a metal halide or high-pressure sodium bulb, depending on your preferences. You only need a basic reflector to mount, and you will be well on your way to growing some healthy plants, but be prepared for small yields come harvest time. 

Dimmable ballasts

If you opt for the MH or HPS option, consider using a digital ballast. These will allow you to lower the amount of power the light will receive. Dimmable ballasts are an excellent way to reduce electricity bills, lower the temperatures of the stealth grow box, and still provide top-quality lighting.

Reflective material and controlling light breaks

If you have been eyeing up an old cupboard, wardrobe, or small storage room, the next thing is to buy yourself some reflective mylar. Reflective material will optimize the lighting in your space. I prefer diamond mylar because it has a better reflective quality; however, that is just my opinion, and most options should work fine. 

Light breaks can be a problem not only for the plants but for you when you are trying to sleep at night. Do your best to cover any spaces where you can see light breaks, which can be tricky with cupboards and anything with hinges. If an external light, from a bedroom light or window, for example, can enter the stealth grow box, plants will begin to hermaphrodite, producing male and female flowers, resulting in a seeded crop.

How to build a stealth grow box

Here’s my step-by-step guide to building a stealthy grow box. It is based on converting a wooden wardrobe.

Materials

• 1 x 4 inch TT inline fan
• 1 x 4 inch carbon filter
• 1 x 4 inch aluminum ducting
• 1 x grow light (LED / HPS / CFL or T5 lights)
• 1 x 15-minute segment timer
• 1 x clip on fan / stationary fan
• 1 x diamond mylar 2 meters square size

Assembly

• Step 1 – Mark a 4-inch diameter hole in the top part of the wardrobe for where the extractor will sit. Cut out the hole, making a clean finish.
• Step 2 – Do the same at the bottom part of the wardrobe. This will be where the fresh air is pulled in from. 
• Step 3 – Line the inside of the wardrobe with the diamond mylar, ensuring there are no air bubbles. Try not to crease the mylar when fitting the corners. 
• Step 4 – Connect the TT inline fan to the carbon filter using the aluminum ducting. Using ducting tape, make sure the fitting is tight and cannot come off.
• Step 5 – Hang the TT fan and carbon filter using chain and hooks at the highest point in the wardrobe. Feed the ducting through the hole made in step 1. Your extractor is installed.
• Step 6 – Set up the grow light. Make sure the light is around 6–12 inches below the extraction when hanging your light. 
• Step 7 – The top half of the cupboard contains the grow light and extraction. Now, add a stationary fan on the floor or oscillate for airflow. 
• Step 8 – Insert 6 inches of aluminum ducting into the 4-inch hole at the base of the wardrobe. Cover the ends with pantyhose to create a dug and bug cover.
• Step 9 – Now, add your pots or hydroponic system, plug in your timer, and you now have a stealth grow box complete with extraction, lighting, and a fan!

My final thoughts on stealth grow boxes

Over the last 20 years, I have tried all types of stealth grow boxes, built my own customized hydroponic systems, mastered SCROG in small spaces, and now have the luxury of growing outdoors in Spain. 

That being said, if I could give any tips and advice to a first-time grower with a budget of a few hundred dollars, it would be to read Robert Bergman’s Grow Bible and play around with small-sized converted cupboards and wardrobes, then step up to grow tents. Having an airtight tent with zero light breaks is a game changer, ensuring consistency with temperature, air exchange, and crop quality.