"Horse power cave" microcab build - for MH+HPS(+CO2 in future)

Chester da Horse

Well-Known Member
The Elephanta Caves: Stage II
<<<<<< The Temple of Ganja >>>>>


I'm in the last few weeks of flower of my first grow and am building out a new cab for the next run. It will be a sealed environment with CO2 eventually, but I will probably be exchanging air to start with. Any input would be appreciated guys...

My biggest worry to start with is ventilation, with mind to adding CO2 in future


  • Under stair space:
    • 42"/1060mm height
    • 35"/900mm width
    • 56"/1420mm depth
Cave II.jpg
(the photo shows 110cm on the tape measure, and the ruler is 1m long)​
  • ziggurat style recessed rear wall
    • perforated diffusion panel between grow space and a false cavity below the lower steps > for future CO2 generation system
  • lighting
    • 250W MH in cooltube in rear
    • 400W MH/HPS (SonTAgro) in Sunsystems Lowrider II aircooled hood
  • ventilation
    • Extraction: 6" 270cfm/460m3h canfan pulling through carbon filter and 7.5m of 6" ducting to heat diffusion chamber with exhaust vents to outside
    • separate HID cooling: 6" axial computer fan drawing fresh cave air and pushing through 6" cooltube and SunSystem LowRiderII aircooled hood, exhausting back into surrounding cave
    • passive air intake through inlet at cave mouth
  • oscillating fan (23cm) for air circulation
  • dehumidifier (250W, 16L/24hr capacity)
Future upgrade plan:
? Use carbon filter and 6" as recirculating scrubber in a sealed cave?
? Add 8" fan and scrubber system for extraction
? Add CO2

So questions:

Does my 6" fan have enough power to exchange the air often enough to start with (before I add CO2)???
-The box is a bit more than 1 cubic meter / 45 cubic feet in volume,
- it needs to suck through the carbon filter
- and push through 7m of 6" duct with 2x 90-degree bends

What would the best way to supplement carbon be? a tank and regulator is what i'm thinking. can't afford a ppm sniffer just yet.
 
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SirGreenThumb

Well-Known Member
Personally I don't think you need the co2. But as for your extraction fan, no its not big enough. I have an extraction fan that is a little over 500cfm in a tent that is 6x2x3 connected to a carbon scrubber feeding through my cool tube (400 watt hps) and it manages to keep it below 73 degrees F.
 

Chester da Horse

Well-Known Member
Personally I don't think you need the co2. But as for your extraction fan, no its not big enough. I have an extraction fan that is a little over 500cfm in a tent that is 6x2x3 connected to a carbon scrubber feeding through my cool tube (400 watt hps) and it manages to keep it below 73 degrees F.
Well you have justified my concerns about my ventilation, how many CFMs do I need?. could i use my shitty 6" computer axial fan as a duct booster in the exhaust side of my ducting run and get away with out a new fan now?

have you run CO2 and been disappointed? would a mid range (800ppm) CO2 boost give 10-20% yield gain if other conditions were optimised? I started thinking about CO2 mainly because of the ventilation problem - so I can have a sealed room and get away with a lower rate of air exchange.

I don't plan on doing many runs a year - just enough to grow for myself - so any way I can reap a bigger harvest in these small spaces would be great.
 

SirGreenThumb

Well-Known Member
Its really hard to determine.
What is the standing temperature under those stairs? Where are you planning on exhausting heat to?

I have never used co2 as I know that we as humans breathe it so it stands to reason that if you spend time with your plants the oxygen you are producing is co2. Not sure as to how much but I believe I read that we expel around 2.5 pounds a day. Something like that but you obviously wouldn't be spending all day in there but co2 is usually on a timer. Honestly you would have to talk to a co2 expert on that issue as I've never felt the need for it.

Your best option in my mind is to get everything setup the way you want it, try to minimize the bends in your duct and turn on your light and let it run with your fans and everything and see where you stand.

I wish it was as easy as just setting everything up and knowing exactly the fan for your space but with all the knowledge that someone obtains they can never really tell you what is going to work in your exact space unless you design it to their specification of what it should be.

Get it setup and hook up the equipment you have and then see where your at and I can attempt to help you further.

Lastly that computer fan isn't really going to provide anything but more than a hassle for you. One its not designed to be a duct booster so you will have to cut holes your duct thereby making it where even more needed air escapes. Then you have motor and everything that will add heat to the inside of the duct.

I can show you links to my grows if you need to be sure I can grow. LoL

Just ask. :wink:
 

SirGreenThumb

Well-Known Member
Honestly if I were you I would find somewhere to exhaust that air and then the majority of your issues will be solved.
 

SirGreenThumb

Well-Known Member
Sorry for my rambling I have been smoking on this hyper version of pineapple express I've had curing for a month.

pe1.jpg

Same pineapple express with different lighting. PEbud.jpg

My current cross: Super Haze + GDP + Purple voodoo cross.jpg
 

Chester da Horse

Well-Known Member
@SirGreenThumb - I like it, a lot! should be three different posts, so i can like it three times bro! That is boner weed for sure

The shit I'm growing now is the best weed I've ever smoked - Australia must be starving for good genetics. So easy to grow, and sit down before you read my smoke report...

Top cola harvested day 50 at mid canopy height. Wet trimmed weight > 11g. Dried 48hrs then blow dried and spun out in a spliff.
This is it...


I'm fucking a candy flavoured, tropical UNICORN!
smoking-horse-wallpapers_26653_1280x1024.png.jpg
with a
rainbow coloured mane on a fruit salad train high in the Kashmiri mountainside. Flying through a sandalwood and cedar forest on rails of ice, slicing through crisp smokey air - no harshness or burn just a delicate sapor. There's sunshine and butterflies, but no goats.

The bouquet is wild jungle flowers and pungent (one stick drying for 48hrs in my bedroom and the reek is upliftingly heavenly). The terpene profile pleases the senses with passionfruit giving way to DD melons and a whiff of methyl butyrate

She's frosty as fuck to the naked eye - really furry pistils, but turning yellow fast. Her sisters from the same seed packet are green and purple!!!
Miranda Kerr at 2012 VS Fashion Show-14.jpg
last bit of top cola.jpg
Miranda Cola Day 50.jpg

HELP ME GROW MORE OF THIS !!!
 
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Chester da Horse

Well-Known Member
2 more weeks.
Thanks for dropping in, any suggestions for my grow cab in first post?

I do respect ya bro you can grow. (I AINT MAD AT YA)


2 more weeks will be 64 days. Strain guide says 60 days, I like a cerebral sativa high (which I got mothafucka!)

I'll pick the top colas at day 60 at the crack of dawn, and see if the lower ones fill out a bit

But they're still banging on fresh white pistils so I'll keep checking trichs and hold on, I already took 3 colas over the last week to kill the cravings.

@SirGreenThumb - you got those off 400W HPS? thats my goal now, teach me! I will get the cab painted, setup with fan/lights, and get back to you with environmental parameters, hold tight.
 
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Chester da Horse

Well-Known Member
Content of CO2 in expired air from humans = 4.5% =45,000 ppm
Target concentration for grow box = 800 ppm = 0.08%
Volume of grow box ~ 1m3 = 10^9 mm3
Total CO2 available content in box at any time needs be Vol x [target Conc] = 8x10^5 mL
The volume of expired human air that contains this much CO2 is [target CO2 content in mL] / [conc] = 17777777.7778mL 1.7x10^7 mL
My respiratory tidal volume is about 400mL/breath = 44000 breaths
/10 breaths a minute = 4400 minutes / 185 hours / 7.7 days of breathing to reach target concentration and then continue to make up for what the plants uptake for photosynthesis during lights on...

So If get 8 people to breath into my cab for one day and then sit in it while lights are on it might work.

Am I right?

EDIT: corrected for days / hours miscalculation. My bad
 
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SirGreenThumb

Well-Known Member
Content of CO2 in expired air from humans = 4.5% =45,000 ppm
Target concentration for grow box = 800 ppm = 0.08%
Volume of grow box ~ 1m3 = 10^9 mm3
Total CO2 available content in box at any time needs be Vol x [target Conc] = 8x10^5 mL
The volume of expired human air that contains this much CO2 is [target CO2 content in mL] / [conc] = 17777777.7778mL 1.7x10^7 mL
My respiratory tidal volume is about 400mL/breath = 44000 breaths
/10 breaths a minute = 4400 minutes or 185 days of breathing to reach target concentration and then continue to make up for what the plants uptake for photosynthesis during lights on...

So If get 190 people to breath into my cab for one day and then sit in it while lights are on it might work.

Am I right?
LoL, I have no idea.

If you have your heart set on using CO2, do it. I was just saying that a vent hole would be your best option.
 

Chester da Horse

Well-Known Member
5hit just got real 8) I can expand the cave and create a hidden grow room with flower cab (1.8m H x 900mm W x 1m) 5tay tuned for

5tage 5555: 5tory of a 5ecret 5tealth grow cave

 
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Chester da Horse

Well-Known Member
5ecret 5chematics:

Lighting
  • Flower cab: 1.8M high x <1.2m wide x 1.2m
    • 600w lumitek digital ballast
      • Phillips 600W Agro plus HPS lamp in aircooled Sunsystems Low Rider II hood
  • Veg cab: ziggurat style recessing rear wall: 70cm at rear > 1.6m at front x 900m wide x 1.5m deep
    • 400w lumitek digital ballast
      • 400w MH or 430w SonTAgro HPS lamp in aircooled Sunsystems Low Rider II hood
    • 250w magnetic ballast
      • 250w MH in aircooled cooltube
Ventilation
Talked this over with hydro store junior, he reckons it might work. I'll set it up give it a test run to measure the environment. If this fails I'm open to suggestions, my backup is to get a 450cfm+ 8" fan, silencer and scrubber but it will cost $800-$1000. Which is out of range at the moment.
Intake: grill into centre room, with dehumidifier (250w) running
Exhaust for whole system:
6" canfan (220cfm) sucking on carbon filter which is in the smell space > 3m of insulated 6" ducting with another 6" axial computer fan inside as duct booster. Exhausts into vented cavity separate to grow space. No bends in run

Exhaust for flower cab:
6" duct linking 600w lowrider hood to smell space

Exhaust for veg cab:
6" axial computer fan ($90) pushing through 6" duct and 250W cooltube and 400W lowrider hood > 2m 6" duct > smell space
 

Chester da Horse

Well-Known Member
Progress report

-Framed and concrete gutters complete plus a few wall panels are up 1.jpg
-smell box is constructed and ready to install at rear of flower cab
smell box gap.jpg

Im thinking of not using pots for flower and just chucking hessian bags on the bare earth floor for the plants to grow through, anyone think its a good or bad idea?
flower cab floor.jpg
 

Chester da Horse

Well-Known Member
me in cave.jpg And its done...

flower light and smell box.jpg veg cab.jpg electrical.jpg

Temps are low 20s, RH 50-60%.
Total of 1250w of lights running,
Actual power draw is 1400W/5.8A on 240V at the socket (including ballasts, fans, dehumidifier)

The smell cab seems to work.

Just need to seal for air/light leaks, mount the door hinges and lock build muffle box for the main fan.
 
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