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A few questions about using an air pump


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El_Piraña
2 hours ago, Mush Zombie said:

Good question. I love RH drill downs.

Yes, you are correct about warmer air being able to hold more moisture, relative to the size of its container. The molecules expand as they get warmer, and therefore hold more water. Because RH is relative to the space of the container and the temperature, this is also why it is harder to maintain a high RH at warmer temperatures. There will only be so much moisture available in that space to fill the molecules.

When the air cools, it is easier to fill with moisture, and therefore easier to maintain a high RH.

Condensation, however, is a phenomenon related to dew point. Condensation usually occurs when the sides of your container are colder than the air inside of the container. Like a cold beer on a warm day, the moisture in the air will condense on the cooler surface, if it is below the dew point.

When condensation is occurring this will reduce the RH of the container, since moisture is condensing from the air on the walls of the container.

I have always used condensation as an indication that the air inside of a container is too warm. The goal should be no condensation. Mycelium produces its own heat and c02. Being too hot in the container can cause several different issues, from not-so-potent mushrooms to cobweb mold, and as you said, uneven pinsets.

I prefer low RH tubs with a good casing that holds a good amount of moisture. 50/50+ comes to mind. I do not mist the tubs until the casing is almost dry. That is how you know you're getting good evaporation, which is what causes the mycelium to pin in the first place. Leaving a casing too wet too long causes many other issues.

So with a casing: low RH 70%-85% (never above 85%), good air flow to allow casing to dry out mostly before misting again. Doing it this way you don't really have to fan unless airflow has decreased and the casing isn't drying out fast enough. With experience this formula will make a lot of sense and your eyes will be able to judge on their own if conditions are correct. You will also be able to experiment with speeding drying of the casing, and slowing it down so you don't have to mist often. Finding the middle ground between misting and not misting is what I try to achieve these days. I don't fan much, if at all.

Drying out the casing too quickly once pins have formed will cause very small mushrooms, so tighten up airflow once you see pins to get some (relatively) larger mushrooms with a big pinset.

Thanks for the explanations.  I looked up dewpoint on wikipedia for more:

Quote

The dew point is the temperature to which air must be cooled to become saturated with water vapor. When cooled further, the airborne water vapor will condense to form liquid water (dew). When air cools to its dew point through contact with a surface that is colder than the air, water will condense on the surface.

I'm thinking it through a bit more and can come up with some nuances about the dewpoint, condensation and temperature.  On my tubs there is some condensation on the inside walls of the tub, so that must mean that the temperature of the walls of the tub is below the dewpoint inside the tub.  But outside the tub it is still above the dewpoint since there's no condensation on the outside.

Also, I would guess that the temperature inside the tub might be ok even with condensation, this could be verified easily enough w/ a thermometer.  But your rule of thumb is probably good advice based on normal room temperatures.  Unfortunately I don't have a lot of options to cool down my tubs here, so I still fruit them at higher than ideal temperatures.

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Mush Zombie
3 hours ago, El_Piraña said:

Thanks for the explanations.  I looked up dewpoint on wikipedia for more:

I'm thinking it through a bit more and can come up with some nuances about the dewpoint, condensation and temperature.  On my tubs there is some condensation on the inside walls of the tub, so that must mean that the temperature of the walls of the tub is below the dewpoint inside the tub.  But outside the tub it is still above the dewpoint since there's no condensation on the outside.

Also, I would guess that the temperature inside the tub might be ok even with condensation, this could be verified easily enough w/ a thermometer.  But your rule of thumb is probably good advice based on normal room temperatures.  Unfortunately I don't have a lot of options to cool down my tubs here, so I still fruit them at higher than ideal temperatures.

Outside of the tub is of no consequence since the space is larger, and not the space inside of tub. The reason the outside walls are cooler is because of the outside environment, which is separate from the inside of the container. The formula for RH is water pressure x space x temp (in laymen terms) ((no offense. psychrometry is my job)). We should look at the inside of the container as its own earth with its own atmosphere.

The air temp inside the tub, when there is condensation inside the tub, is generally 10*f warmer than than the air outside of the tub, depending on several other things, including elevation.

The rule of thumb is what works, for you. You can drill down the math and algebra. Or just simplify it!

You are on the right track though. These equations are not simple for anyone, even if some that does this for a living thinks its obvious, as myself. I certainly don't mean to be condescending (pun intended huehueh).

If you want to talk more about psychrometrics, let me know. There is much to be learned!

Either way, you are doing great. Anything can be improved. However, we must always decide whether the payoff is worth the investment.

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Moonphase
36 minutes ago, Mush Zombie said:

Outside of the tub is of no consequense since the space is larger, and not the space inside of tub. The reason the outside walls are cooler is because the outside environment which is separate from the inside of the container. The formula for RH is water pressure x space x temp (in laymen terms) ((no offense. psychrometry is my job)). We should look at the inside of the container as its own earth with its own atmosphere.

The temp inside the tub, when there is condensation inside the tub, is generally 10*f warmer than than the air outside of the tub, depending on several other things, including elevation.

The rule of thumb is what works, for you. You can drill down the math and algebra. Or just simplify it!

You are on the right track though. These equations are not simple for anyone, even if some that do this for a living think its obvious, as myself. I certainly don't mean to be condescending (pun intended huehueh).

If you want to talk more about psychrometrics, let me know. There is much to be learned!

Either way, you are doing great. Anything can be improved. However, we must always decide whether the payoff is worth the investment.

Psychrometric ratio

The psychrometric ratio is the ratio of the heat transfer coefficient to the product of mass transfer coefficient and humid heat at a wetted surface. It may be evaluated with the following equation:[5][6]

where:

 = Psychrometric ratio, dimensionless

 = convective heat transfer coefficient, W m−2 K−1

 = convective mass transfer coefficient, kg m−2 s−1

 = humid heat, J kg−1 K−1

 

Damn MZ I looked up Psychrometry, the field of engineering concerned with the physical and thermodynamic properties of gas-vapor mixtures, and your field of expertise is way over my cerebral capacity... and I always thought I was pretty smart.  Sublimation, condensation, dew point, Rh, were all difficult subjects during ground school when I was 15 but now I try not to think that hard.   Kind of gives me a headache.  :thinking:

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Mush Zombie
55 minutes ago, Moonphase said:

Psychrometric ratio

The psychrometric ratio is the ratio of the heat transfer coefficient to the product of mass transfer coefficient and humid heat at a wetted surface. It may be evaluated with the following equation:[5][6]

where:

 = Psychrometric ratio, dimensionless

 = convective heat transfer coefficient, W m−2 K−1

 = convective mass transfer coefficient, kg m−2 s−1

 = humid heat, J kg−1 K−1

 

Damn MZ I looked up Psychrometry, the field of engineering concerned with the physical and thermodynamic properties of gas-vapor mixtures, and your field of expertise is way over my cerebral capacity... and I always thought I was pretty smart.  Sublimation, condensation, dew point, Rh, were all difficult subjects during ground school when I was 15 but now I try not to think that hard.   Kind of gives me a headache.  :thinking:

I never think I am smart. I cannot recommend that anyone should ever think they are smart. There is so much all of us do not know and will never know. Never underestimate what you are not aware of.

keep learning!!

2 hours ago, El_Piraña said:

Thanks for the explanations.  I looked up dewpoint on wikipedia for more:

I'm thinking it through a bit more and can come up with some nuances about the dewpoint, condensation and temperature.  On my tubs there is some condensation on the inside walls of the tub, so that must mean that the temperature of the walls of the tub is below the dewpoint inside the tub.  But outside the tub it is still above the dewpoint since there's no condensation on the outside.

Also, I would guess that the temperature inside the tub might be ok even with condensation, this could be verified easily enough w/ a thermometer.  But your rule of thumb is probably good advice based on normal room temperatures.  Unfortunately I don't have a lot of options to cool down my tubs here, so I still fruit them at higher than ideal temperatures.

To cool down the tubs loosen the lower poly fill or whatever filter you are using. You may also need to add a positive pressure device, like a small fan. You may need to adjust the top filters as well. Keep a close eye and you will see. c02 needs to be released from the container. it is heayy and flows the like water compared to air, and will also pull fresh air through though the top filters, as it escapes the bottom filters.

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El_Piraña
37 minutes ago, Mush Zombie said:

I never think I am smart. I cannot recommend that anyone should ever think they are smart. There is so much all of us do not know and will never know. Never underestimate what you are not aware of.

keep learning!!

To cool down the tubs loosen the lower poly fill or whatever filter you are using. You may also need to add a positive pressure device, like a small fan. You may need to adjust the top filters as well. Keep a close eye and you will see. c02 needs to be released from the container. it is heayy and flows the like water compared to air, and will also pull fresh air through though the top filters, as it escapes the bottom filters.

Cool, I’m gonna give this a try when I get back home.  

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DrDankness

Mush Zombie, i think im gonna case and try to keep humidity lower as now my situation has changed some and i dont think i will be able to fan and mist 3x a day (that would be every 8 hours right? Not just 3x when the light is on?). Will the micropore tape work ok or do i need polyfill? And by tighten up airflow do you mean like cover the holes halfway or all the way with another layer of tape? And if i used polyfill how would i tighten it up? Close off holes?

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El_Piraña
50 minutes ago, DrDankness said:

Mush Zombie, i think im gonna case and try to keep humidity lower as now my situation has changed some and i dont think i will be able to fan and mist 3x a day (that would be every 8 hours right? Not just 3x when the light is on?). Will the micropore tape work ok or do i need polyfill? And by tighten up airflow do you mean like cover the holes halfway or all the way with another layer of tape? And if i used polyfill how would i tighten it up? Close off holes?

You can easily change the airflow by increasing/decreasing the amount of polyfil that is stuffed in the holes.

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DrDankness

Ok cool. Thank you guys for all this info! You have been more than patient with my noob questions. Ive failed 2x in a row now and just want ONE harvest. 

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Moonphase
On 2/7/2021 at 2:04 PM, DrDankness said:

Ok cool. Thank you guys for all this info! You have been more than patient with my noob questions. Ive failed 2x in a row now and just want ONE harvest. 

Failure is only failure when you do not learn something from the outcome.  I've grown some great Trichoderma in my experiments and had some big $100 failures in inoculation, spawn run, and fruiting.   Last year was the first time in 5 or 6 attempts that I got a 3rd flush with absolutely no trich.   Temperature.  Rh.   FAE.  All strains have their favorites.  Not to mention sterile conditions.   It's a lot to balance effectively.   :hippie:   

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DrDankness
4 hours ago, Moonphase said:

Failure is only failure when you do not learn something from the outcome.  I've grown some great Trichoderma in my experiments and had some big $100 failures in inoculation, spawn run, and fruiting.   Last year was the first time in 5 or 6 attempts that I got a 3rd flush with absolutely no trich.   Temperature.  Rh.   FAE.  All strains have their favorites.  Not to mention sterile conditions.   It's a lot to balance effectively.   :hippie:   

Its mainl;y just that ive been putting money into this for like 2-3 months now and havent gotten any thing. Its just been money going out and me getting nothing. Fingers crossed i get atleast something this time! This is as far as ive made it haha

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DrDankness

Well i think im fucked before i even spawn.... All the jars had this. Its mold right? Could it be because i did MSS to LC? I dont really have the space or equipment to do agar at the moment. And hard to keep everything in a super sterile area as we have a cat and a dog.

image0 (1).jpeg

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DrDankness

Well it seems everyone is telling me its normal and im fine. It didnt look like normal myc to me so i kinda freaked out

 

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Moonphase

Looks like good healthy white mycelium to me.  I'd say it's time to PC some substrate so it's nice and sterile and get to mixing up some tubs for a spawn run.   :headbang:

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DrDankness
On 2/9/2021 at 10:43 PM, Moonphase said:

Looks like good healthy white mycelium to me.  I'd say it's time to PC some substrate so it's nice and sterile and get to mixing up some tubs for a spawn run.   :headbang:

I just started my spawn run and im 3 days in and already have myc poking through the top. ^^

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