Rate my DIY custom box build & super new with a few questions!

OceanGreen44

New Member
(( Pics at bottom ))

Hi All,

Almost too much info on this site. Thanks in advance to everyone that at one point answered someone elses random questions to reference and get my build off the ground.

First my requirements were absolute stealth. No exceptions. Plus to hide this it needed to be very compact for where I will be installing it. So I looked up some high end grow boxes and was stunned at the prices. Yeah - time to build my own. I have a background in construction so always have scraps of this or that laying around. (But I think i screwed up already...)

Here is the rundown.

1/2" Wood construction - 36L x 36W x 16D
Internally sealed with caulk and a sealant. (Internally waterproof/mold/etc).
Rubber stripping around the doors for light/air full seal.
AYR-FOIL a2a Reflective liners.
5" Duct inline fan + 1 elbow joint connector
16" Custom chicken wire interchangeable mesh carbon scrubber
300W LED full spectrum grow light.


I actually think looking at this thing that I over-constructed the shit out of it. The 5" inline is rated for 170cfm, and those 4 passive intakes seem to be able to not whistle and still have some really good suction force out to in. I guess the scrubber isn't too thick and the fan is right for the total airflow. Maybe too strong? Isn't that better? lol

To make the scrubber I rolled up some chicken wire to the 5" diameter of the duct fan. Then took a "mesh" shower liner.( Stupid name. looks like the fishtank nets but huge sheet for the shower. dollar store!) and hot glued a pouch if you will, the width of the chicken wire. Roll it around for the length and complete the pouch leaving a little opening for a funnel to pour the active carbon into. After rinsing the carbon for dust to get it wrapped around hehe rolling pin. flatten to the LxW of the full "pouch" that was made. Flat the carbon is a bit less than 1.4" thick. lay this pouch on top of the huge cut-to-fit carbon pads (online/fish stores) and roll it up around the chicken wire cage.

I did it this way because these inline fans hate pipe size reductions in short ranges (often causing severe blowback). Using the 5" pipe and building outside the cage instead of in allows the fan to push full opening into the scrubber for almost 2 feet once it crosses the fan. Plus I can quick-change the filter in literally 5 seconds with pre-made ones as time goes on.

*****
Questions
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Overall I think it will work but I now see that plants, well, get massively taller. Did I screw myself over by only being able to make it exactly this size for the placement?

LST & Scrogging will be a must in my case I guess, but I'm worried that it's still too short. I can move the light up a bit to gain a max of 30" clearance from floor to light. Seems like that will cook everything like an oven still?!

Also the heat and humidity worries me. These LED's were not supposed to get hot hot... will the following be a problem? (5h empty box run for temps)

Room Temp / Humidity = 70F / 51%
Box Temp / Humidity = 84F / 32 %

So if that is too hot I think due to the loving Canadian weather about to start would be to drop the room heater a few notches and let the box pick up the slack of evening out the heat difference, in theory cooling down the inside in the process?

I can tell my building skills are vastly superior to my green thumb haha.

Thanks for the help, and criticize away! Everything is tweak-able before starting. ;)


 
re: Rate my DIY Custom Box Build & Super new with a few questions!

I bought one of those little ones online like you talk about was about $400 with light, and I realized right away after getting two clones in it that height was going to be a problem real soon as it was only 3 feet tall and footprint was going to get crowded as it was 8"x14". So I tried to mimic it and make one on my own out of a cabinet I bought at Habitat for Humanity Used Building Supplies place, it turned into two lol....can see them in this thread, can read more if you want (yours looks more professional than mine (been a Millwright in the past so a Jack of All Trades and Master at None ;) ) and whether I have a green thumb or not is yet to be determined though I did get thru my first grow completely and got something to harvest), it seems to change out the air enough with the computer fans so your setup for air should be plenty:

The Anti-Journal Journal

LED's put out the least heat (or from what I have read anyway) so would be worse with a HPS or MHS type lights.
 
re: Rate my DIY custom box build & super new with a few questions!

Im no expert but do explain how the carbon scrubber works outside the box as they are made to have the air sucked in and not pushed thru?...i see its home made but im thinking to neutralize the smell...the same principal applys!
 
Thanks urban. You sound like me lol. I can build one waaayy cheaper and bam! Too small oops!

I guess time will tell how it will work out.

Anyone take a guess of the temps? Won't the plants fry?

@wally - yes externals work by pushing through he filter. Goes like. --->|box|=fan direction=>|filter|==out into room=>

Your fan just has to be strong enough to create a negative pressure inside the box.
 
Thats interesting cause i have seen many people say you only suck thru carbon to neutralize smell.....you never push.....its so hard to tell who actually knows their shit here lol! So your saying as long as there is negative perssure i can blow thru a carbon filter right?
 
I've read that too all over the place. I think it depends on the setup. I've seen pics of both ways and nobody followed up so I can't vouch for either way.

Logically I don't see why it wouldn't work. Airtight box with fan pulling negative keeps all smell inside by airflow design. Exhaust outside house no filter needed, exhaust inside house need to scrub. Where the filter is before it hits "the room air" is irrelevant IMO. As long as the internal air passes through the scrubber to rejoin the room.

I guess doing it my way won't work with low end fans. If it cant generate enough force it will cause fan blowback, and in turn leak air backwards from the passive holes. This is actually very common when installing ducts and stuff if you dabbled. The fans are notorious for this, so I went big enough to be able to push a slight faint breeze through aprox 1/2" total of both carbon materials.

That's my logic on it. Never grew before just brainstorming.

Real world I threw a ziplock bag of tomatoes in there and couldn't smell anything at all for 24h until I opened the doors. So it seems to work just fine.

I can only tell you for sure on a live plant in a few weeks. (Gonna start a grow journal for help along the way)
 
Just tryin to make sure you got it the right way lol .....i am in the same boat just waiting on my card...i have done a bit of reaserch on it.....i dunno if you want to compare tomatoes to flowering plants either though.....good luck hope it works for ya.....the box looks great too...space seems to be the real issue i guess.....i still say shes gonna stink to high hell blowing thru though
 
Get a big bag of stinky and open it in there then try lol.....although i still think its gonna smell more on the plant in full bloom....worth a try though lol
 
Thanks buddy!

I know it's vastly different from live plants, was a quick and dirty test.

Worst case I can pop the fan off the elbow and do a snake U path down then up again. Put the inline fan at the end and ring the inner ducting with carbon circle cutouts that sandwich in loose carbon. With enough length the airflow shouldn't be that weak that the fan can't aggressivly evac it.

Time will tell I guess!

Edit: yes a big bag.. that's what I meant by tomatoes... Cough cough. lol ;)
 
Thanks urban. You sound like me lol. I can build one waaayy cheaper and bam! Too small oops!

I guess time will tell how it will work out.

Yeah the little pre-made one with light was just over $400, I ended up with two bigger boxes with a bigger light for both for under the cost of the little one. I didn't realize how cramped it was going to get until my first box when I got a couple plants in it and then went "hmm not going to be able to Veg these very long as they will get too big and be too close to the light before they done growing", but that box turned out to be perfect for seedlings and small clones for early stages (now I have a box for each stage ;) lol).
 
It's a bit discouraging honestly. Annoying actually...heh. I assumed with an auto strain and heavy lst stuff it would be manageable. Hell I've seen posts of people growing in red cups. Figured this box for a single one would be overkill.

Well this is all it can be if it is to be. Where are those cup grow people to chime in lol. This section of forums visited often?
 
Looks like I probably cant use this box now that i'm testing a bit further.
Not with this light anyways...

Isn't the lux range about max 70,000 @ the grass outside on any given sunny day?

Seems like I'm pulling 3x+ as much... like the distance of Mercury from the Sun or something?!?!
Won't that cook everything to death ?

Devil's question here -

Worth even bothering at this point or just make a taller box and convert this one to CFL for seeding etc ?

 
It is nice to have more than one, that way you can have plants at different stages (1 or 2 in Flower and smaller ones in early veg). It just comes down to having more room and of course more money lol. The 150W LED you can find pretty cheap, my little box (3' tall) came with one of those and it seems to work pretty good to me.
 
Hi again everyone !

Just an update for anyone that comes across this thread researching info. (I didn't die. needed to move "to mexico" haha)

Short version - BOX CRAP - FAN thingy EXCELLENT !

In doing this test I nearly lost a plant. setup was fine. the plants just get too big. Like hands on scrog non stop and you cant limit it down enough to not cook under the light, they just get far too close and burn. I cant figure out how those online 2x2 metal boxes online don't cook it to death. Maybe they do, dunno. (In testing I converted upwards into a tall bookcase style. this is the lowest acceptable height IMO. To give light clearance etc)

Anyways! The FAN filter thing !!! works great actually! the catch ? unless you have aquarium stuff lying around, and some decent chicken cage wire, the prices have gone down so much for the "can filter only" style (90$ CDN with taxes for a can-lite 2600). That building this will basically cost you the same - minus the lifetime swap guarantee. Also the store ones are much lighter in weight for hanging in tents btw.

BUT it does work, so if you do actually want to build one, yes. 100% works to eliminate. It will last 1 run, then you need to bathtub wash it out (just like aquarium ones) to reactivate etc.. then re-use. Near the very very VERY end, honestly I would say MAYBE a 1% noticeable aroma starts in the room IF you have a really long 8-9+ flower stage.

As for the "fan". I've gotten sooo much hate from the people who saw my new setup with that same 4" duct booster OMFG... but it works. and is quiet enough that there is no jet noises.

I'm going to mark a note that this might all be possible due to the canada environment in general. It's not humid up here, and heat doesn't exist. So the LED's producing no heat, ambient room temps around 72 and you need to work to boost humidity - It's possible that the setup works great in these conditions - but the duct fan for instance won't be enough to pull through muggy south heat temps, to the level of proper circulation and not kill your friends.

I've upgraded to a 4x4 tent now and left behind the stealth boxes for the moment (4x4,1k led,same duct fan,can-lite lite filter). After going through all this, I can say that if you have the materials lying around, yes it does work- with some slight fiddling. If you have to start buying a few things to build something like this? Stop. Just get a small 1x2 or 2x2 grow tent. It will cost you the same in the end as building. Needs vs Situation in the end.

Happy building !
 
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