DIY Budget Closet Grow Box

Please do not post until you see some half-baked m&m's.

Here are the details to a grow box (actually, more like a cabinet) that I just built to house my second grow. Other than the dimensions, much of this design is modeled after my first grow box, which resulted in success considering it was my first grow. I figured I would put this out there for anyone looking to get ideas for building a budget grow box that will fit in a closet. I won’t go into details for everything, but hopefully still enough so that a few of you can walk away with some ideas. I also won’t go into details about the lighting, as that’s not really the point of this grow. But I will provide some info about my lighting set-up at the end.

The dimensions of the box may seem a bit awkward, but the shape allows me still use the closet for storage, as well. I did not have to buy too many materials since I had much of the below lying around the house. I’ve also included some prices (estimates).

Materials:
- Wood -$20
- Poster board - ?
- Duct Tape - $6
- Reflective Duct Tape - $6
- Aluminum Foil - $4
- Foil Tissue Paper - $8
- Screws - $4
- Nails

Box Dimensions:
5’6” tall, 3’8” wide, 15” deep
Plan is to house 3 plants in this box.

you helped me out a little bit thanks
quick question would it be better to use a white tarp for reflection or tin foil

Construction:

For wood, I purchased the following from Home Depot. You will want to cut your wood based on the dimension of your box.
(6) 1”x2”x8’ cut into:
- (4) 5’6” pieces
- (4) 15” pieces
- (4) 42” pieces
- (1) 50” piece
- (1) 42" piece

Construct wooden frame starting with the end pieces.



Here's the final frame. The “T” in the front of the frame is for the doors to my grow box.

The panels are built out of posterboard. I know some people argue that you should not use anything but wood to build a grow box due to fire hazard, but here are some things to consider.

Ignition points (temperature where material will catch fire and continue to burn):
Wood – 380 – 870 degrees Fahrenheit, depending on type of wood
Paper – 451 degrees Fahrenheit
I personally don’t buy the argument that wood grow boxes are safer than cardboard grow boxes. Hell, some grow tents are made out of fabric. The way I look at it, whatever is going to cause a posterboard or cardboard box to burn will most likely burn down a wood box along with the rest of your house. The key to having a safe grow box is having a safe electrical and lighting set-up. I know not everyone will agree with what I just said.

Okay, so back to my set-up…

The 1x2 wood has the tendency to warp, so I knew my box would not have perfect right angles. As a result, I cut the posterboard to the shape rather than just measuring and cutting. I laid the frame on the posterboard, outlined the shape and used a utility knife to cut out the panels.



And all the cut out panels.

I then lined all the posterboard with aluminum foil. Why? Well despite my earlier statement that the key to a safe grow box being safe electrical and lighting… I still wanted to add some “insurance.” Aluminum foil burns/melts at very high temperatures. For all of you grillers and campers, I’m sure you have all made food pouches which are thrown right into burning hot coals. Aluminum’s melting point 1220 degrees Fahrenheit. So I decided to line the panels basically as a heat shield.

Here's a panel completely lined with aluminum foil and getting ready to line it with "mylar."

neversummer28 said:

The panels are built out of posterboard. I know some people argue that you should not use anything but wood to build a grow box due to fire hazard, but here are some things to consider.

Ignition points (temperature where material will catch fire and continue to burn):
Wood – 380 – 870 degrees Fahrenheit, depending on type of wood
Paper – 451 degrees Fahrenheit
I personally don’t buy the argument that wood grow boxes are safer than cardboard grow boxes. Hell, some grow tents are made out of fabric. The way I look at it, whatever is going to cause a posterboard or cardboard box to burn will most likely burn down a wood box along with the rest of your house. The key to having a safe grow box is having a safe electrical and lighting set-up. I know not everyone will agree with what I just said.

Okay, so back to my set-up…

The 1x2 wood has the tendency to warp, so I knew my box would not have perfect right angles. As a result, I cut the posterboard to the shape rather than just measuring and cutting. I laid the frame on the posterboard, outlined the shape and used a utility knife to cut out the panels.

And all the cut out panels.

Click to expand...

is that that "dry erase marker board" stuff? I actually thought about using that but went with panda film instead.. I think that board stuff is a good idea. +rep

The next step is one I leave up to you. You could simply leave the panels just covered with aluminum foil, but I’ve seen many arguments online about foil having hot spots, and ultimately, leaving burn marks on the plants. But you also read those people who said they have used aluminum foil for years without ever experiencing any burns.

I added another layer of “mylar” over the aluminum foil, primarily because I wanted a more reflective surface. Since this is a budget grow box, I did not purchase a roll of mylar. Instead, I went to Partycity and bought 2 packs of silver tissue wrap. No, it’s not actually tissue paper, it’s just called that. You get 15 sheets that measure 20" x 30" each for only $3.99! That's 9000 sq. inches or over 62 sq. ft. Can’t beat that.


I used the shiny kind of duct tape to attach the “mylar” to the panels. The shiny duct tapes allows me to have a reflective surface throughout the box. Here's a completed panel.

Before you attach any of the panels to the frame, make any cut-outs needed!!! Such holes for fans, lighting, cords, etc. It will make your life much easier. I made a holes for my exhaust fan and to allow my electrical cords to run out of the box.

I attached all the panels to the frame using small nails, similar to the ones found with those bookcases that you have to assemble by yourself. I then used the shiny duct tape to seal everything inside so absolutely no light, air, etc will leak out. This involves taping the panels to the wooden frame, covering all the exposed wood, and taping over any other gaps that might be in the box. I literally sealed the entire box. I also sealed the edges on the outside of the box with regular duct tape.

Neither of my side panels go entirely from the top to bottom. I left a 10" gap on both sides on the bottom in order to allow air circulation.

On the one side, I also made the panel so that I can open it up further in order to allow more airflow in case it gets too hot. It is simple flap which is held closed and open using velcro.

Here's the side panel with the built in flap.


And here it is with the flap open. You can also see how I built the bottom of the box. It is lined with a plastic trashbag in order to give some water protection just in case of any spills or small overflows. It is sealed tightly with duct tape to prevent any leaking.

I could not make swing doors due to space issues – instead, I made removable panels. The panels are attached to the "T" part of the wooden frame. Measure carefully with the doors in order to make sure that the least amount of light leaks out. You want to have all the edges come together closely. You can use weather insulator to make it even more light-proof.

Here's the completed box without the doors. You can see my inline duct fan in the top right which exhausts air out. I will eventually make a homemade carbon filter to fit over the exhaust fan.



Here's what the grow box looks like with one of the door panels off.


And here's what the grow box looks like in my closet.

Alright, and as promised, here are some details about my lighting, all from my first grow.

My main bulb is a 250W Agrosun Bulb. It contains both MH and HPS so it can be used through the entire growth, both vegetative and flowering. I believe I paid approximately $80 for it at my local hydroponics shop.

I also purchased the ballast and socket at the same time. It is the Lumatek Electronic Ballast, for up to 250W bulbs. I honestly do not remember how much I paid for it, I believe around $80, as well.

The socket is the Hydrofarm All Systems Cord set, and I believe I paid about $20 for it. Don't hold me to either of these two numbers.

For my first grow, I had a homemade reflective hood made out of ducting. For this second grow, I decided to fork out $25 for a batwing hood. I'm hoping those dimples do spread the lighting a little more.

All of these were purchased at my local hydroponics shop who's prices are better than online prices (shipping costs is the difference maker).

I also compliment this 250W bulb with 4 additional CFLs. I made some DIY sockets using materials purchased at Home Depot. I have daytime bulbs for the vegetative stage and soft white bulbs for the flowering stage -- all bought from Home Depot.

According to the guy at my local hydroponics shops, he claims that CFLs sold at gardening shops are better for plants since they provide more specific colors from the spectrum that the plants use. I'm sure there's something truth to this, but my first grow termed out pretty damn well using regular CFLs.


Wrap It Up
In this grow box, I plan on growing 1 Masterkush, 1 Super Lemon Haze and 1 White Widow.... all DWC. I will start a journal soon, so keep an eye on my signature. You can check out my first grow as well, link in my signature.

So that basically the set-up for my grow box. Hope it gives some of you some ideas. The most important thing I can suggest... as with building anything... measure twice, cut once. Good luck!

xXJDMXx420 said:

you helped me out a little bit thanks
quick question would it be better to use a white tarp for reflection or tin foil

Click to expand...

you actually posted before i finished... but i used "foil tissue" bought at party city. See above.

regarding white tarp, i think that should work well. in all my research, people seem to always recommend mylar (or something similar) and just flat white paint. so i imagine the white tarp would be similar to white paint.

regarding aluminum foil, i mentioned it above, but some people claim it causes hot spots and can burn your plant. but i've also heard many people say that's a load of crap. to be safe, i'd say go with the white tarp.

so is it dry erase board or not?

What did you spend in the end. Looks alrigt. I was very skeptical about the poster board Idea. I would have used wood on the bottom. Or at least do a tray. It wouldn't take much to scratch the tin foil or tissue paper and let water into your poster board, Good luck, I think I will stick to wood and mylar

420OldSchoolDJ420 said:

so is it dry erase board or not?

Click to expand...

hahaha, not quite oldschooldj. but that's not a bad idea for the next grow. might come in handy considering i'm usually high when i'm taking care of my plants.

wonderblunder said:

What did you spend in the end. Looks alrigt. I was very skeptical about the poster board Idea. I would have used wood on the bottom. Or at least do a tray. It wouldn't take much to scratch the tin foil or tissue paper and let water into your poster board, Good luck, I think I will stick to wood and mylar

Click to expand...

hey wonderblunder,wood is definitely the way to go if budget allows for it. but the posterboard was free to me. i've found prices on the internet where you can get something like 5 large sheets (i used 6) for under $20.

i def agree with you about the bottom... i like the tray idea. i'll take a look around to see what i have available to reinforce the bottom.

if budget wasn't a concern, i'd go with wood and myalr too. just throwing an idea out to the RIU community for those who are like me and need to get creative with money. but for this grow, i'm investing most of my money into nutes, supplements, and also going to buy myself a ec/tds/ppm meter. thanks for the suggestions.

neversummer28 said:

hahaha, not quite oldschooldj. but that's not a bad idea for the next grow. might come in handy considering i'm usually high when i'm taking care of my plants.



hey wonderblunder,wood is definitely the way to go if budget allows for it. but the posterboard was free to me. i've found prices on the internet where you can get something like 5 large sheets (i used 6) for under $20.

i def agree with you about the bottom... i like the tray idea. i'll take a look around to see what i have available to reinforce the bottom.

if budget wasn't a concern, i'd go with wood and myalr too. just throwing an idea out to the RIU community for those who are like me and need to get creative with money. but for this grow, i'm investing most of my money into nutes, supplements, and also going to buy myself a ec/tds/ppm meter. thanks for the suggestions.

Click to expand...

Great job on the construction.. Thanks for taking great pictures and writing it up. Great work showing what can be done on a budget.

This is the exact design of my "baked potato" setup, I did not use foil or posterboard, but my frame was made out of metal, it had a mesh that covered 3 of the 4 sides, so i attached the mylar to that, and insulated the outside with whatever i could find, my setup is double the width of yours and i'm using a verity of flourcents for now. 11260 lumens is what i got for 10 square feet and 9 plants, I plan on using this tent just for vegging, and using a HID setup in the same design for flowering. Wondering your thoughts on that?

kloak said:

This is the exact design of my "baked potato" setup, I did not use foil or posterboard, but my frame was made out of metal, it had a mesh that covered 3 of the 4 sides, so i attached the mylar to that, and insulated the outside with whatever i could find, my setup is double the width of yours and i'm using a verity of flourcents for now. 11260 lumens is what i got for 10 square feet and 9 plants, I plan on using this tent just for vegging, and using a HID setup in the same design for flowering. Wondering your thoughts on that?

Click to expand...

Baked pototo set-up... I like that. It works great for people like us who are on a budget.

As for your lighting, I think you're a bit low with the lumens. With 11260 lumens at 10 sq ft, that turns out to be only 1125 lumens per sq ft, which is extremely low. A lot of people recommend at least 2500-3000 lumens per sq ft. You can never have too much lighting, just keep in mind... the sun emits about 10,000 lumens per sq ft.

snow4aaron said:

Great job on the construction.. Thanks for taking great pictures and writing it up. Great work showing what can be done on a budget.

Click to expand...

Thanks man, so many ways of making grow boxes, I figured I'd just add to the pool of ideas.

neversummer28 said:

Baked pototo set-up... I like that. It works great for people like us who are on a budget.

As for your lighting, I think you're a bit low with the lumens. With 11260 lumens at 10 sq ft, that turns out to be only 1125 lumens per sq ft, which is extremely low. A lot of people recommend at least 2500-3000 lumens per sq ft. You can never have too much lighting, just keep in mind... the sun emits about 10,000 lumens per sq ft.

Click to expand...

yeah, im the process of replacing my 3 bar lights with 16 CFL's which should help a great deal, if the price turns out to be over 200 .....i'll get a nice hid setup, im already planning on buying one within the next month or so for my flowering setup. the bar lights will be used on the sides once i get my top lighting figured out. This is what i've spent so far.


$20 for the mylar, They come in 3 dollar packages, I got about 6.
$25 for the main fixture and 2 40'' bulbs.
$20 for the smaller fixture and the 20' bulb.
$15 for the shop light fixtures and reflectors.
$15 for the CFL's for those fixtures (27w)
$10 worth of duct-tape and Nylon rope, Rope being used to hang the fixture and tie the 2 curtains in front closed.