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BuddyGreen
tripping

Registered: 07/20/04
Posts: 264
Last seen: 9 years, 25 days
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Monotub theory
#17987536 - 03/20/13 11:28 PM (11 years, 9 months ago) |
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What's up everyone? So I've been reading different tek's for monotubs, but they all seem to lack any real theory behind the placements of their holes on the monotub. More just instruction manuals on how to make one. If I'm going to do this, I want to actually understand what's happening, not just be like READ INNERWEBZ, DRILLED WHOLEZ, GOT SHROOMZ!
I notice a lot of different placement and size on different teks and mono tub images I've seen. There's always at least 2 at the level of the substrate. I understand hole size will effect the GE and FAE, so it's not size I'm worried about. I want to know why people place their holes in different spots throughout the tub. My guess is the holes that are level with the substrate increase FAE, since they're at the same level as them.
Where else do you guys place your holes? And why?
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BuddyGreen
tripping

Registered: 07/20/04
Posts: 264
Last seen: 9 years, 25 days
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So there's really no one on here that has any theory about their hole placements??? It's just DRILLD HOLEZ GOT SHROOMZ? Come on, help me learn!
Do higher holes promote more humidity by allowing the dry air to escape from the top?
I really just want some explanation of why some of you put your holes where you do on your monotubs based on environmental factors or whatever, so I can make the best, educated decision on where to put my holes.
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mountain whiskers
Silly Goose


Registered: 06/20/12
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Last seen: 10 years, 11 months
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its not rocket science, just prevent stagnant air pockets, holes on top holes on bottom.
edit: keep enough holes to allow for air exchange but not so many it drops humidity. i notice strongest side pins below my holes, so im sure smaller holes spaced out more would be good..
i think it is just easier to regulate 6 holes with poly more so than 20 smaller ones
Edited by mountain whiskers (03/21/13 02:12 PM)
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FrankHorrigan
The Inquisition



Registered: 01/04/11
Posts: 10,573
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The hole positions don't matter much as long as you got some higher up and some substrate level.
Stuff polyfill tight on bottom holes and loose on top. Run a fan on low in the room facing away from the tubs. This allows for fresh air to come in the top holes and be forced out the bottom. This also allows for proper RH at substrate level.
EDIT: edited for posters further down the thread.
Edited by FrankHorrigan (03/22/13 12:02 PM)
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StygianKnight
A Mushroom

Registered: 03/12/12
Posts: 2,717
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People like different patterns or find what's easiest to cut. The airflow is too slow for it to matter with exact placement. It's not like air is flowing in one way and out another.
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FrankHorrigan
The Inquisition



Registered: 01/04/11
Posts: 10,573
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Quote:
StygianKnight said: It's not like air is flowing in one way and out another.
It should be air in the top holes, out the bottom. That's why you should stuff the bottom holes extra tight and the top very loose
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BuddyGreen
tripping

Registered: 07/20/04
Posts: 264
Last seen: 9 years, 25 days
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Quote:
mountain whiskers said: its not rocket science, just prevent stagnant air pockets, holes on top holes on bottom.
edit: keep enough holes to allow for air exchange but not so many it drops humidity. i notice strongest side pins below my holes, so im sure smaller holes spaced out more would be good..
i think it is just easier to regulate 6 holes with poly more so than 20 smaller ones
Thanks for the reply! When you say strongest side pins below your holes, do you mean you've noticed your pinset growing faster/stronger right closer to the holes by the bottom?
And that's basically all it does, allows FAE while sustaining the desired level of humidity?
Quote:
FrankHorrigan said: The hole positions don't matter much as long as you got some higher up and some substrate level.
Stuff polyfill tight on bottom holes and loose on top. This allows for fresh air to come in the top holes and be forced out the bottom. This also allows for proper RH at substrate level.
Quote:
BuddyGreen said: It's just DRILLD HOLEZ GOT SHROOMZ?
Don't be such a condescending jerk next time 
Ok, so we want the air escaping through the bottom, because that's where our fruits are and they benefit from the air exchanged and the relative humidity being concentrated more towards the bottom? Thanks, that makes a ton of sense.
And I'm sorry, I didn't mean to come off as condescending. That was more just my attempt at humor :P perhaps I'll add more emoticons when I try that. I just noticed a lot of monotub 'how to's' that were just telling me where to drill holes, and not really explaining WHY I was drilling though holes... ergo "DRILLHOLEZ GETS SHROOMZ!" I didn't mean to offend you.
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thundahoof
S+laughter


Registered: 02/03/13
Posts: 951
Last seen: 11 years, 3 months
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Quote:
RogerRabbit said:
Quote:
An older post, " Fresh air comes in through the top holes and pushes the heavier C02 out of the bottom holes. This is the basic philosophy behind a mono-tub and why it works."
The lack of physics understanding by members here is underwhelming at times. CO2 mixes with the air as science has known for centuries. It does not settle to the bottom of a ventilated tub, nor does it get 'pushed out' bottom holes. 
CO2 mixes with the air and goes where the air does. In my mushroom farm, the CO2 level is 200 ppm higher near the ceilings than near the floor. Why? Because of convection and the fact that warm and humid air rises. When the CO2 mixes with this warm and humid air, it rises too.
Substrates create heat. Lighting creates heat. These factors cause convection in the tub. Nobody can map exactly what the currents are doing because they'll constantly change based on ambient weather conditions of humidity and atmospheric pressure, as well as whether your light is on or off, etc. RR
From here: http://www.shroomery.org/forums/showflat.php/Number/17962236/page/2
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mountain whiskers
Silly Goose


Registered: 06/20/12
Posts: 373
Last seen: 10 years, 11 months
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yeah they love the area below the holes...

you want air moving out the bottom holes to push the co2 off the substrate i think and help with surface evap.
Edited by mountain whiskers (03/21/13 02:32 PM)
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FrankHorrigan
The Inquisition



Registered: 01/04/11
Posts: 10,573
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Quote:
thundahoof said:
Quote:
An older post, " Fresh air comes in through the top holes and pushes the heavier C02 out of the bottom holes. This is the basic philosophy behind a mono-tub and why it works."
That is absolutely not what I was saying. But when you have tight poly on the bottom and loose on the top, fresh air comes in the path of least resistance and leaves through the bottom holes. Of course the CO2 is mixed with the circulation. Your RH and FAE will be much better with tight poly on the bottom and loose on top.
Quote:
BuddyGreen said: Ok, so we want the air escaping through the bottom, because that's where our fruits are and they benefit from the air exchanged and the relative humidity being concentrated more towards the bottom? Thanks, that makes a ton of sense.
And I'm sorry, I didn't mean to come off as condescending. That was more just my attempt at humor :P perhaps I'll add more emoticons when I try that. I just noticed a lot of monotub 'how to's' that were just telling me where to drill holes, and not really explaining WHY I was drilling though holes... ergo "DRILLHOLEZ GETS SHROOMZ!" I didn't mean to offend you.
Sorry, I misunderstood 
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BuddyGreen
tripping

Registered: 07/20/04
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Last seen: 9 years, 25 days
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Thanks thundahoof, So from RR's older post, he says that CO2 isn't pushed out, but it rises with the hot and humid air. , so the co2 at the bottom of the bin is lower then that at the top of the bin... Is this because there's less air escaping from the top, due to smaller holes, and the fact that heat rises? Does O2 expand whenever it's hotter, allowing more CO2 to mix with it? Since mushrooms don't have chlorophyl and don't produce their own food, do the levels of CO2 and O2 at the substrate level matter?
mountain whiskers - thanks, the sure do look like they love those holes
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FrankHorrigan
The Inquisition



Registered: 01/04/11
Posts: 10,573
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 Did you read my last post? It has nothing to do with CO2 going out the bottom or wherever else. That's not what happens. When you have tight poly on the bottom and loose on the top, fresh air comes in the path of least resistance and leaves through the bottom holes. Of course the CO2 is mixed with the circulation. Your RH and FAE will be much better with tight poly on the bottom and loose on top.
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mountain whiskers
Silly Goose


Registered: 06/20/12
Posts: 373
Last seen: 10 years, 11 months
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lol, you are gonna turn this into rocket science or thermodynamics arnt you. you could debate that the substrate is generating heat and micro currents pushing air upwards i suppose. i just have my poly in loose and sometimes no poly in the top holes at all. but it is 90% humidity outside here, and i have a giant saltwater fishtank that keeps the whole house pretty humid, so my subs dont dry out very much with the loose poly.
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BuddyGreen
tripping

Registered: 07/20/04
Posts: 264
Last seen: 9 years, 25 days
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Quote:
FrankHorrigan said:
 Did you read my last post? It has nothing to do with CO2 going out the bottom or wherever else. That's not what happens. When you have tight poly on the bottom and loose on the top, fresh air comes in the path of least resistance and leaves through the bottom holes. Of course the CO2 is mixed with the circulation. Your RH and FAE will be much better with tight poly on the bottom and loose on top.
Sorry, I don't think I contradicted anything you posted, I'm clear on the fact that we're not trying to "push" out CO2, I didn't think that was the case anyways. I was more or so asking about the distribution of the co2, not the fact that there's DEFINITELY going to be CO2.
Since RR said the top of his bin has higher concentrations of CO2 then the bottom, and heat rises, I was just wondering if the reason for this was because CO2 can be distributed more widely within O2 at higher temperatures, possibly because of space between molecules at higher temps.
Whenever temperature rises, relative humidity drops, so by having looser polyfill at the top, and tighter polyfill on the bottom, this allows more air to circulate through the top, which is also going to be the warmer air, and keep the temperature constant, allowing relative humidity to stay the same? Correct?
hahahah mountain whiskers, I'm sorry if I am turning this into a thermodynamics discussion. I just feel like the more I know about what is actually happening in my tub, the better I'll be able to adapt, bringing me the best fruits ;]
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FrankHorrigan
The Inquisition



Registered: 01/04/11
Posts: 10,573
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RH will drop as the fresh air enters. It causes the moisture on the surface of the substrate and walls to slowly evaporate. This loss of moisture is a major pinning trigger.
Humidity is trapped by the polyfill more less depending on how it is stuffed.
Your tub will stay a couple degrees F hotter than the room it is in. This creates condensation as moisture is sucked from the air on to the walls. This lowers the RH and also causes evaporation from the surface of the substrate.
Since the air is circulating, the CO2 and O2 are going to be mixing constantly. The specifics of how much CO2 is where is completely irrelevant and could only be determined by your own testing. The idea is that the monotub should have passive FAE 24/7. In such a small tub, the tiny CO2 gradient that might exist is really just a moot point.
Air circulates, evaporation occurs, old air goes out, mushrooms grow
Edited by FrankHorrigan (03/21/13 03:59 PM)
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thundahoof
S+laughter


Registered: 02/03/13
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Last seen: 11 years, 3 months
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DRILLED WHOLEZ, GOT SHROOMZ!
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353
Stranger

Registered: 03/20/13
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Last seen: 11 years, 9 months
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Quote:
thundahoof said: DRILLED WHOLEZ, GOT SHROOMZ!
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BuddyGreen
tripping

Registered: 07/20/04
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Last seen: 9 years, 25 days
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Thanks Frank One thing I find inconsistent with your answer and my research though is the introduction of fresh air dropping relative humidity. Since the bin will always be a few degrees higher then the room it is in, wouldn't stuffing your holes with polyfill allow more [cooler] air into your monotub, actually increasing relative humidity?
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mountain whiskers
Silly Goose


Registered: 06/20/12
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is your outside air >90% humidity?
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BuddyGreen
tripping

Registered: 07/20/04
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Last seen: 9 years, 25 days
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Quote:
mountain whiskers said: is your outside air >90% humidity?
I don't believe it is at this time. But it will definitely start to rise in the next month or so.
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