Yet Another DIY Grow Cabinet

Hello, all! I recently started my first grow, in a DIY grow cabinet I made out of a ClosetMaid wardrobe purchased from Home Depot. I started planning the build last fall, and went through countless different iterations in my head before settling on this. Props to Cobra420 and his dual 150 watt HPS cab for unknowingly providing the inspiration to finally lock in the design!

This is a dual 250 watt MH/HPS set-up with a mom/clone chamber on top. The bottom left and right grow chambers measure approximately 23"/20"/48" (width/depth/height). I don't have light #2 yet, but will be ordering it within the next couple of weeks. The top chamber measures 48"/20"/20" (again, w/d/h) and currently has a single 65w, (actual, not equivalent) 6500k, 4,000 lumen CFL (I plan to replace that before too long, but haven't yet decided on exactly what I want to use).

For ventilation I opted for a sort of goofy-looking system that I hope to eventually upgrade and replace with the tried-and-true darkroom louvers. I just didn't have the funds this time around; those things are pricey! I bought all my ventilation materials for the price of two 8x8 louvers. Here's what I did:

I attached a 1/4" plywood backing to the cab, and drilled two 4" holes in each of the three chambers - one each for intake, and one each for exhaust. I ran lightproofed 4" flex-ducting from the exhaust ports in the two bottom chambers up to a T-connecter that opens into the top chamber. For intakes in the bottom chambers, I coiled lengths of the same blacked-out ducting, and put 4" straight connecters at the end, wrapped in pieces of a Honeywell carbon filter pad. The intake for the top chamber is simply a 4" connecter with filter (doesn't need to be lightproof). The carbon filter sits in the mom chamber and vents through a 4" PowerMaxx blower attached to the top of the cab. It looks a little like a Gorgon, but damn if it doesn't work well! There is gentle negative pressure from about half-speed on the fan controller, and at full I need to give it a good firm tug to open the doors.

Fortunately, a stealthy appearance is not a concern, as the cab is in a locked basement. So why build a cab at all? The basement is unfinished, and is not tapped into the house's ductwork, so it tends to get pretty damn cold three seasons out of the year. I figured it would be more difficult to control the environment in a thin tent. And I like the sturdiness of the cabinet.

For a control panel I attached a piece of the plywood to the side of the cab. I wanted everything on the outside so that I can adjust things without having to open the doors. I'll be mounting another ballast and another power strip with another timer.

I sealed the cab with black caulk and aluminum HVAC tape. The wife did a lot of the taping, which is why it looks so uneven (and I did get her permission to blame her!); I'm thinking that at some point I'll go back over the seams to pretty it up.

I'm using 1/2" weatherstripping to seal the doors, and damn if that whole thing isn't a royal pain in the ass! It took us three nights of work just to get the damn doors hung. I've done plenty of reading on DIY cabs, so I was expecting this to be the most difficult part of the build, but holy shit... I'm still not 100% confident on the lightproofing, so I'm going to get an inner tube, or something of the sort, and attach it to the inside seam of the doors.

I planted two HSO Black D.O.G. seeds last week, and will be putting them into the left chamber under the 250w MH as soon as they're good and rooted. In a couple of weeks, I'll be planting three HSO Blue Dreams - those will go in the right chamber, again under a 250w MH. Planning to scrog on both sides. This is an organic soil grow, by the way.

I think that's it! Nothing groundbreaking or especially clever, but it's mine and I built it, so I'm proud nonetheless. I'm sure I have already made some mistakes, and I expect I'll make plenty more, but at least I finally started growing. I'm on my way!

I love a good cabinet build. Good luck with your first grow. Have you done any temperature tests yet? 250 watt in that area is a lot of light, If you can keep it cool enough, you should be fine.

ReikoX said:

I love a good cabinet build. Good luck with your first grow. Have you done any temperature tests yet? 250 watt in that area is a lot of light, If you can keep it cool enough, you should be fine.

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I did indeed. So far, everything's good. The basement really is very chilly. That may not remain the case once the heat of summer hits, but I do have a back-up plan if temps get out of control.

Thanks for the well wishes!

I like the fact that you used 250W instead of 150W i have tried both on some cabinets that i have, the 250W perform so much better!
The heat is a problem yes, i usually have the doors cracked as i keep them in a spare room.
I dont bother with MH anymore as there is more blue in better part of spectrum in full spectrum HPS...No need to change globes. the HPS works all the way through.

Moved the seedlings down from the mom/clone/germ chamber to the bottom-left grow chamber. Temperatures weren't completely out of hand, averaging in the mid-eighties, with the MH 12 inches from the plants. What was out of hand was the humidity - or lack thereof, rather. With the exhaust turned as low as the temps would allow, the humidity hovered in the mid-twenties. Yikes!! Tried adding a cup of water, then a pan of water, then hung a wet towel... No luck. So, I went out and bought one of those little cool mist humidifiers. Having read up on the subject, I was worried that my exhaust fan would just suck the mist out before it had a chance to do its thing. Thankfully, after leaving it in there for hours, I opened it to find the humidity in the mid-fifties, and it's been holding since then. Whew!!

noodles05 said:

I like the fact that you used 250W instead of 150W i have tried both on some cabinets that i have, the 250W perform so much better!
The heat is a problem yes, i usually have the doors cracked as i keep them in a spare room.
I dont bother with MH anymore as there is more blue in better part of spectrum in full spectrum HPS...No need to change globes. the HPS works all the way through.

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I have the challenge of combating cold as well as heat. At lights out, I point a space heater at the intake - otherwise the temps drop into the 50's (Fahrenheit, by the way). So far so good, except for one time when the wife moved the space heater WAY too close. By the time I checked the cab myself, humidity was at 17% and the temp was 102°!! The plants seem okay for the most part; the color is good and they haven't wilted, but I do have small spots of curling At the middle point of the edges of the first two leaves of the biggest plant. No other leaves were affected, which seems odd? I might post a pic in the infirmary to get some feedback from people who actually know what they're doing - unlike myself!

Subbed.

Humple W. said:

I have the challenge of combating cold as well as heat. At lights out, I point a space heater at the intake - otherwise the temps drop into the 50's (Fahrenheit, by the way). So far so good, except for one time when the wife moved the space heater WAY too close. By the time I checked the cab myself, humidity was at 17% and the temp was 102°!! The plants seem okay for the most part; the color is good and they haven't wilted, but I do have small spots of curling At the middle point of the edges of the first two leaves of the biggest plant. No other leaves were affected, which seems odd? I might post a pic in the infirmary to get some feedback from people who actually know what they're doing - unlike myself!

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Hi Humple W
What system are you running for watering? If your going for hydro...(flood & drain drip etc) you can use a fish tank heater for the nutes, this will keep the cupboard warm at night also without a hitch. the space heater draws excess power. if not, it will take a good hour for the root zone to come up to temp with the light on...not too long.
Low humidity is not a problem, its actually preferable for less disease & mold, + it usually means good air flow for Co2 & oxygen.
I wouldnt worry too much about the curling at the moment, as it has already occured from heat stress.
A good rule of thumb is..If you feel comfortable in that environment then so will the ladies
All the best mate.

noodles05 said:

Hi Humple W
What system are you running for watering? If your going for hydro...(flood & drain drip etc) you can use a fish tank heater for the nutes, this will keep the cupboard warm at night also without a hitch. the space heater draws excess power. if not, it will take a good hour for the root zone to come up to temp with the light on...not too long.
Low humidity is not a problem, its actually preferable for less disease & mold, + it usually means good air flow for Co2 & oxygen.
I wouldnt worry too much about the curling at the moment, as it has already occured from heat stress.
A good rule of thumb is..If you feel comfortable in that environment then so will the ladies
All the best mate.

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I'm just hand-watering soil for now. But thanks for the encouraging words! You've definitely made me feel better about the state of these plants. Thanks to everyone for being such a helpful resource for this rank amateur!

Just a quick update. The plants have been in the bottom left chamber, under the metal halide, since the evening of 5/12. The daily dance of turning on the space heater and turning off the humidifier at lights-out continues. I have the feeling that climate control will continue to be a challenge unless I finally get my ass in gear and run some ductwork from the HVAC system into the basement. But I persevere regardless!

Have you thought about picking up a couple of cheap timers to do that dance for you? It would be a quick fix, but give you time to finish running your HVAC to the basement.

ReikoX said:

Have you thought about picking up a couple of cheap timers to do that dance for you? It would be a quick fix, but give you time to finish running your HVAC to the basement.

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I was thinking about doing exactly that, actually. I have one spare timer (Apollo something-or-other - two-outlet digital unit), and I planned to try it out, but the space heater is all digital, so I'm wondering if it'll even kick on with the timer? No mechanical switch sitting in the on position, waiting for power. But yeah, I need to at least try it. Also thought about switching to a 24-hour veg cycle as a means of mitigation. What do you guys think of that?

Humple W. said:

I was thinking about doing exactly that, actually. I have one spare timer (Apollo something-or-other - two-outlet digital unit), and I planned to try it out, but the space heater is all digital, so I'm wondering if it'll even kick on with the timer? No mechanical switch sitting in the on position, waiting for power. But yeah, I need to at least try it. Also thought about switching to a 24-hour veg cycle as a means of mitigation. What do you guys think of that?

Click to expand...

You will have to try the digital heater, but it may not work that way. I'm not a fan of 24h light personally. I believe plants need a rest period.

ReikoX said:

I'm not a fan of 24h light personally. I believe plants need a rest period.

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I totally agree. I usually go with a 18/6 when im growing indoors. I feel that the dark period far outweighs the extra hours of light.

Also, subbed, ill be watching this one. Good luck!

Small update: my temps in the veg chamber have been holding at around 79°F, (which seems pretty good to me) but now that the plants are getting bigger, the humidity is going up. Actually had to turn the humidifier off to stay under 50%. So, since the humidifier was helping to keep the temps down, I figured I'd better compensate for the absence of that cool mist, so I pulled a 120mm PC fan from an old machine I had lying around, hooked it to a 12v adapter, and attached it to the reflector, opposite the bulb. I used coated copper wiring to tie the fan on. Not sure of the gauge, but it's just pliable enough to be easily bent into shape, and just rigid enough to easily hold that shape. Brought the temp down 5 degrees, without the aid of the humidifier. Not bad, but this fan is weaksauce. I'm sure I could dig up a more powerful one, but I don't want to cannibalize any of the working computers in the house, so I may order something better if temps creep up later in the grow cycle.

Also, two days ago I started germinating three HSO Blue Dream seeds in the top chamber. Won't be long before I start using the bottom right-hand chamber. That's when we'll really see how well I can keep the temps in check, with two metal halides running simultaneously in small, adjacent spaces. Here's hoping everything goes to plan!

Oops. I thought I had attached pics. Here's the fan setup.

I popped three HSO Blue Dream seeds last week. Still in the mom/baby chamber, but it won't be long before it's time to move them into veg. This leaves me in a bit of a pickle...

I had planned to buy my second ballast and reflector in time for the second crop, so the plants could go in their own chamber (and not interfere with my scrog plans for the Black D.O.G. that's vegging right now), but now I'm having difficulty finding one that doesn't look really damn sketchy. The one I currently have is a ReVolt model; from my understanding this is sold (made?) exclusively by Gotham Hydroponics. They've been out of stock for weeks, and apparently they don't know how to respond to emails, because I've sent them three now, asking when they'll have stock again, but they haven't responded. Any recommendations?

This has given me another idea though - what do you guys think of running a cheapo China LED fixture for a while? I was looking at the Roleadro 400 (200w) COB and it's twin, the Lightimetunnel version. From what I've read they're reasonably well-regarded as a purely budget-focused, entry-level light, albeit with a worrisome component failure rate, but by all accounts the customer service is excellent, and they happily replace parts that crap out, at no extra cost (and with fast shipping). I've also read of some people upgrading the COBs with higher quality parts, but I don't know if that's wise or not? The thing is, they're only $100, and the idea of tossing a cheap, effective (at least for a while) light in the cab, while saving money on power and greatly reducing the heat (which isn't needed now, but I expect will be very welcome when we start getting 90°+ weather). This is also attractive from a variety perspective; I could learn some of the differences between HID growing and LED growing.

So what do you guys think? Do I need to be talked down? Am I thinking of making a big mistake here? Should I just hold out? Drop some wisdom on me, folks...

Okay, now I'm going down a rabbit hole. Been researching LEDs for the past couple days, and my head's spinning. Everybody's on about these quantum boards, and I see the HLG 135w kit recommended here and there. It's a little more costly than what I had planned on, and it's apparently always out of stock, so I don't even know why the hell I'm looking at it, since my concern was getting the second chamber up and running ASAP - but damn if they aren't intriguing. Still, I have no clue what I'm doing, and not the faintest idea of whether or not one of these 135w QB lights could compete with a 250w HPS as far as yield is concerned. Bugger. Anyone familiar with these?

Okay, so I decided to go ahead with the QB light (once it's back in stock). I'll post some pics when I get it installed. Should be very interesting to see how it competes against the 250w HPS.

Upgraded my cheapo EBay reflector to an Adjust-A-Wing Enforcer (the small size). I can finally run the bulb perpendicular to the width of the chamber, which I wanted to do in the first place. Hopefully the smaller physical footprint will improve air circulation as well. Oh, and the light footprint is much improved!

On another note, my quantum board kit should arrive tomorrow. Hopefully I'll be able to put it all together over the weekend and then I'll post some pics. Can't wait to compare the HPS and LED!