Hypobaric Grow Chamber (High Altitude Simulation)?

The idea of high-altitude kush has always fascinated me, seems that some results just can't be replicated at low altitude. Given I can't exactly find anywhere high altitude to move to, I figured why not bring the mountains to my garage.

So I am trying to figure out how to build a hypobaric chamber capable of emulating altitudes of 5000-7000 ft (about 15-25% drop in air pressure). An entry-way to pressure-equalize would probably be needed, but its not really that hard to achieve.

So, assuming you were able to start off with a reasonably sealed environment (walk-in fridge/reefer?(no pun intended)) Would a vacuum be able to be maintained without having to constantly run an exhaust fan? (CO2 injection concerns) Is there an alt. manner to drop air pressure as a whole in the room?
Any other thoughts on this? Ideas?


Basic math behind this:
Pressure @ 0 ft (sea level) 1atm
Pressure @ 7250ft (typical mountain in Afghanistan/Pakistan) (.7-.8 atm)

Thus about a 25% drop in air pressure, which would also mean, out of a 10'x10'x10', (simple math to work with) I would need to remove 25% of 1000 cu ft. or 250 cu ft

*puff* Your hit.

Just be ready to spend big bucks. Good quality vacuum pumps are expensive. Plus dropping to that kind of pressure is going to need better seals than a fridge. You might be able to use an autoclave but an autoclave big enough to grow in is going to be pretty spendy.

i am very interested in this topic, i think there is some mystical weed growin on kilimanjaro and shit

Sounds pretty interesting- at the very least a nice thought experiment. So here goes:

Lowering pressure in a room will be impossible unless it is air tight, so venting air into and out of the room constantly would be near impossible (unless you have an intake valve that would close if the pressure exceeds a certain point, and a one-way valve for exhaust to make sure the pressure stays low- too complex to be practical and too many failure points). What I am thinking of is probably retarded, but it doesn't involve any vacuum pumps or valves. You will have to isolate the plant in a clear tubular dome with a pressure meter that will tell you the interior psi of that vessel. Similar to these, but bigger and longer (I know, I know, that;s what she said):



Place the plant on a platform in a water-tight basin, fill the basin with water, but keep the water from touching the bottom of the plant itself. Place the dome over the plant, allowing the water to collect underneath the dome (with plant inside)- this creates an air tight seal with regular atmosphereic pressure within the dome. To lower the pressure inside the vessel, lift the glass dome up- the weight of the water inside the dome will pull a vacuum on the air inside, lowering pressure; with the pressure meter mentioned earlier you can adjust the height of the dome to match the pressure you are looking for. Much like a barometer, but instead of starting off with a vacuum at the top, you have air for the plant to breathe.


Potential Problems: You will need to have a deep basin of water, and will probably need to raise the glass dome some amount to get the pressure you need, I just don't know exactly how much. Also, the air in the chamber will need to be refreshed at least daily, so it would be high-maintenance. High humidity could result, especially when the temps start getting higher; you can control the temps outside the chamber and that will affect the temps inside the chamber, so if the grow area is well cooled (70-80 deg F) this shouldn't be too bad of an issue. Lastly is the equipment needed for this; water-tight basins are easy to come by or make if need be- the issue will be the dome itself. Glass could work, but it is expensive and heavy, also likely to break. Plexiglass could be used to manufacture a box, but as mentioned earlier it has to be airtight; this would make installing a pressure meter easier, however.

Conclusion: You have a good idea, and it would definetely be cheaper than moving to the mountains, but it will take time and money to do what you are wanting to do. There will also be a great deal of trial and error, but the end result could be some fantastic bug that could only be acquired by flying into one of the most politically unstable parts of the world and flying back with enough bud to make it worth the bother.

If you end up doing this please start a journal or continue on this thread. I would love to see how this would work out.

Peace and good luck.

Just thought on a couple things-

To get the air pressure your want, you will need to raise the chamber the percentage you want to adjust. If the interior of the chamber (from the surface of the water to the top) is exactly 4 feet, you would want to raise it a foot to lower the air pressure by 25% . . . I think. It just seems to make sense to me. So if the chamber is four feet from water to the top, and you are lifting it out by a foot, the actual height of the chamber would need to be around 6 feet; this keeps you from breaking the vacuum,

To make things easier when you need to raise or lower the chamber, put a switch valve at the top. When lowering the chamber to the bottom, leave the valve open. Once the chamber is settled to the bottom of the basin, close the valve and lift the chamber (it will be pretty heavy since it will also be lifting the water with the glass, calculate the volume to determine how much weight the water will add to the setup, a winch system will work best) until you reach the desired pressure.

If is to make more potent bud I think that come's from the higher levels of uvb that does not get filtered out by our atmosphere and nothing to do with pressure anyway!

henery said:

If is to make more potent bud I think that come's from the higher levels of uvb that does not get filtered out by our atmosphere and nothing to do with pressure anyway!

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Damn! I didnt think of that. Now I can stop thinking about that setup. Besides, maintaing a partial vacuum is actually a very difficult undertaking, just ask anyone who works on refrigeration

assasinofyouth420 said:

Damn! I didnt think of that. Now I can stop thinking about that setup. Besides, maintaing a partial vacuum is actually a very difficult undertaking, just ask anyone who works on refrigeration

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. . . and a helluva lot easier than what I was rambling about. + rep on clear thinking henery

Plus hypERbaric raising the pressure.

igothydrotoneverywhere said:

i am very interested in this topic, i think there is some mystical weed growin on kilimanjaro and shit

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How much has to do with lack of oxygen, barometric pressure and whatnot??? AND how much of it has to do with LIGHT???

The particular light spectrum high altitude plants get more of .. UV , the bit of light spectrum traditional indoor plant lights are missing altogether... UV

Where to score some UV spectrum supplemental lighting?? Its all a matter of shopping around, and going to stores you might have overlooked. PET STORES, in the Reptile section have UV-B reptile CFL's and Florescent Tubage.

I am supplementing my flowering plants a little bit. I started mild, with a UV-B 5 CFL. I didnt want to go big, and have it be too big screwing over my plants with too much. I havent seen extra trichomes piling on like they are supposed to in theory... of course I am in about the 3rd week of 12/12 and havent seen the trichome action yet anyway. That plant has been exposed to the UV-B supplemental lighting throughout veg, and I might have to bump up to UV-B 10 to kick in a full effect. I dunno. But it makes sense to me to supplement the UV range, and give my plants a more rounded out real world simulated lighting situation.

Seriously, with or without the hyperbolic chamber.... to fully simulate high altitude your going to have to supplement the UV light. For my money, a $20 - $40 bulb is an easy step in that direction.

Dinosaur Bone said:

How much has to do with lack of oxygen, barometric pressure and whatnot??? AND how much of it has to do with LIGHT???

The particular light spectrum high altitude plants get more of .. UV , the bit of light spectrum traditional indoor plant lights are missing altogether... UV

Where to score some UV spectrum supplemental lighting?? Its all a matter of shopping around, and going to stores you might have overlooked. PET STORES, in the Reptile section have UV-B reptile CFL's and Florescent Tubage.

I am supplementing my flowering plants a little bit. I started mild, with a UV-B 5 CFL. I didnt want to go big, and have it be too big screwing over my plants with too much. I havent seen extra trichomes piling on like they are supposed to in theory... of course I am in about the 3rd week of 12/12 and havent seen the trichome action yet anyway. That plant has been exposed to the UV-B supplemental lighting throughout veg, and I might have to bump up to UV-B 10 to kick in a full effect. I dunno. But it makes sense to me to supplement the UV range, and give my plants a more rounded out real world simulated lighting situation.

Seriously, with or without the hyperbolic chamber.... to fully simulate high altitude your going to have to supplement the UV light. For my money, a $20 - $40 bulb is an easy step in that direction.

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Actually I do use UVB (20mins x 3/day for Bloom, 10.0 lamps, one for each 1k bulb) already, but it seems to me like a lot of strains have protiens that work differently at high alts. The amount of tricomb prod with the UVB light is insane, but I have come to find, not the entire story. Something about the pressure and they way the plant works there is just different.

It would be nice to use that small jar for each plant thing, but I am dealing with 2-4k of lighting at a time per space (considering switching to octagon from drip (all hydro))

The movement of the space I have though about, but getting the hydraulics to do that to a room seems a little hard, as well as sealing something that slides that much.

I simply assumed that a 8" or 10" fan could be used to pump air out, once fan shut off, a backdraft damper would keep air from reversing the fan, and a sally door set to enter (Pressure equalization chamber) I have no problem building the systems to handle air pressure sensors and electronics to operate everything. I was originally hopping to use a refrigerated trailer and seal that to the point of airtight (or as damn close as I can)

I like mushrooms too but to go out on a limb like that... well let's just say you should wind up dead.

tommi002 said:

Actually I do use UVB (20mins x 3/day for Bloom, 10.0 lamps, one for each 1k bulb) already, but it seems to me like a lot of strains have protiens that work differently at high alts. The amount of tricomb prod with the UVB light is insane, but I have come to find, not the entire story.

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That's good to hear, that UV-B supplements actually do something.

Dinosaur Bone said:

That's good to hear, that UV-B supplements actually do something.

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I'm no amateur, I was just looking to see if anyone had an idea of how to create a hypobaric area, about 7x9 or so. I would love to build it as modular units and have 3 or 4 replacing a large room setup. I guess I need to just research air-locks and negative-pressure rooms, but the information is hard to come by, and somehow seems like I am building a chamber that would be the equivalent of a NBC lab(thats nuke, bio, chem) and tends raise some red flags I am not interested in. I don't care too much about the contents of the environment getting out (CO2 leaking out won't fuck people up) just that the air pressure is maintained reasonably.

I wanna still go in and work, if I have to airlock myself (might as well eliminate all sources of bug/mold infestations while I'm at it), or if I build an airlock I break every once in a while to defoliate, etc