Is using yeast to make co2 bad?

This got buried in another thread so started it over here. This is a valid point and could answer a big problem. It really applies to me (it's #3). How much validity is there? I used yeast to make co2 in my grow room.

#1. Plants will use as much CO2 as they are given-- the danger is to the PEOPLE if you use a generator with out a monitor or emergency shut off-- the plants';ll be happy--U B dead!

#2-- the yeast thing does work-- but how much it puts out is iffy... and they only work for a few days before the yeast consume all the sugar then die... you can tell by shaking the jar (or whatever you're using) and if it fizzes-- it's still good... if not- dump it.

#3- you are taking a chance of introducing mold into your grow if it Spurts (often they do) or gets spilled. And yeah-- they smell..

Has anyone else has unexplained mold problems? I had a big problem with mold and was unable to find the source. Cleaned the room. took everything out, spraying with bleach solution, repainting, rehanging lights (after thorough cleaning with bleach also).

You can get the same type of results by doing home-made wine in the growroom (at least 2-3 feet from the plants!) then the plants AND YOU benefit!

something to point out... your yeast population will remain, so when the sugar gets eaten by the yeast, dump out the stale water with yeast left in the bottom, add fresh water and more sugar..
just make sure you dont shake it up before you empty

This is the reason for shaking:

As often as possible shake the container to blend the mixture thoroughly. In one or two days the yeast will grow and co2 will be a by-product in the container. Now, every time you shake it a burst of co2 will be released into the grow room. Also it will continue to be released through the hole in the lid while you are away.

Are those instructions potentially wrong? If you guys think the shaking could be a problem let me know. I will delete from FAQ. Come on guys I need some opinons.

Do you think there is anything to the guys point that the stuff that squirts out of the jug can be a potential mold problem?

no i think the risk factor is low but i use liquid co2 but what doesn't cause mold.

I prefer my timed co2 tanks and solenoids for easy no mess co2 lol mold is yucky

It's a very old post but I just read it and I must ask something, how can a bottle of yeast producing CO2 can kill you? You must be in a very small room, with lots of bottles of yeast, and a very deep sleeper to actually die from it. Sometimes people overreact very easily...
I'm a molecular biology student and yes, if it spills on your plant, it could populate by eating the sugary content of your plant, but if you have a decent setup you can prevent the risk of spilling anything on your plants. Keeping the bottles of yeast away from the plants and sticking a hose or pipette in them should do the trick.

Geneticist said:

It's a very old post but I just read it and I must ask something, how can a bottle of yeast producing CO2 can kill you? You must be in a very small room, with lots of bottles of yeast, and a very deep sleeper to actually die from it. Sometimes people overreact very easily...
I'm a molecular biology student and yes, if it spills on your plant, it could populate by eating the sugary content of your plant, but if you have a decent setup you can prevent the risk of spilling anything on your plants. Keeping the bottles of yeast away from the plants and sticking a hose or pipette in them should do the trick.

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Replying to another old post, he was talking about using a CO2 generator and the risks associated with that. If you are using the yeast+sugar method, you won't ever have to worry about CO2 poisoning.

You would have though someone would have come up with another cheap method of "creating" Co2 in the grow room.

A lot of people spray carbonated water on their plants. Haven't done it myself, would be interested to know if it actually has any effects on growth.

go read the diy on co2 bottles with yeast!

i poured carbonated water straight into the soil my plants were growing in once. it did no harm at all and i got approx an ounce off of each which for my first grow under 250w hps was very unexpected. not sure if this was because of the water or if i was just lucky, maybe ill only do it on 1 of my plants on my current grow and see how it goes???

for every plant how many gallon containers do u need of yeast plus sugar and water setup or is one gallon container for about 4 plants?

hi guys im new here. hows everyone doin? the yeast and sugar. at what ratio do you mix the three? sugar, yeast, and water? i have an 12x12 room.

the yeast thing is a waste of time and money imo. i prefer a water cooled generator the hydrogen pro to be specific. it would be hard for mine to kill me. run that thing for too long and it will get too hot and auto shut off. it used to all the time before i had a 1/10 chiller. the water still get very hot in the 55 gallon barrel. i need a bigger res cause i can only keep my ppms at about 1400. i tried 1800 but the generator auto shutting off from the water getting too hot. i cant run drain to waste as it would not be very economical when im paying for municipal water. so i run recirculating with water pumps and a chiller. everyone seems to worry about it costing too much. well it really isnt all that much. if you can afford a grow with several hps you can afford an expensive co2 gen. bottles work great also! but it sucks having to haul them. even propane bottles suck to carry around. i just like the generator cause the heat helps a bit in the winter time. just sucks in the summer that my electric bill is insane from running allt he extra ac. also when your in the middle of town you dont want to be seen bringing bottles in and out of your place all the time. even though it's legal, ppl like to steal and cameras cant pick out a person wearing a mask.

as far as mold goes, if your talking about powdery mildew, i think the biggest problem is people letting their room temps drop too low during the dark cycle. obviously keeping humidity low also helps. however i was reading in a gardening magazine that a lot of species of powdery mildew do not even need much humidity to spawn. going from a cold temp at dark to a warm temp at light generates plenty of condensation to make life pleasant for the spores. also your strains resistance to mold plays a huge factor. a couple examples i find chernobyl and la confidential to be very mildew resistant. holy grail kush on the other hand really was susceptible the mildew on the buds. also mildew spores are everywhere. you will never get rid of them. you are breathing them in right now. i also spray my garden with azamax 5ml per quart. its safe to spray on the buds and in the light(only with a cool tube) so you dont have to move them out of them room. unless maybe you buds are real close to the light. keeping your room clean only helps slow mold so never hesitate to do so as often as possible. i dont think u can have too low humidity. with how cold it is where i am my humidity gets 20% and i notice no difference from 50%.

lol. You say using co2 is a waste of money and yet you tell us you use a water cooled geni.

To be honest i use it and get double yields.

For the method to work u dont just use yeast and water. That will do nothing and smell rank
You need sugar.

What i do is buy a 3 liter bottle of apple juice (no preservitives , they stuff up the yeast cultures) And then i add 2 cups of sugar and half a capful (very smal cap half a teaspoon) Of breweing yeast , then i put a slow realese pressure cap on and then i give it a nice shake and place it in my grow chamber. It will take about a day To activate.. Then i can ethier leave it in for up to a month (toppping up the sugar lvls every week) Or And this is what i have been doing latly, is i Take it out after 3-5days and Get drunk off it. and i add more.

Oh i also use one per plant.

total cost is around 15 bucks for the yeast and caps (that lasted me almost a year) and 3 dollers per drink. (very cheap IMO)


Also as a side note. Hydro will always produce more from the same strain with a competent grower and using the same system. Also In hydro the water plays a much bigger part as you Will be having Higher nutrient lvls and faster absorption rates.



Also . With the mold issues. Id be checking my humidity first.

I feel this is wrong, unless you're using a generator that has a fire-type source and it's not burning cleanly.. then, and only then could it be a carbon -monoxide- issue. Fatality from CO2 alone would have to result from minimal to no oxygen at all, and extremely spiked level of CO2, resulting in CSHS.

Lol how drunk do you get haha and interesting idea!

To stop contamination of mold from your yeast generator, you need to run your co2 gas through a bubble counter. The bubble counter has vegetable oil in it, when the co2 gas passes up through the oil it filters the co2, and you can, like the name says count the bubbles to see what your co2 production is. You don't need to shake the co2 mixture. If you mixed it right most if the sugar will stay in suspension.

@ smokie, The brew i make acourding to my hydrometer is 8pc. So not to strong but knocks alot of light weights on their bum when they try and drink the full 3 liters.


Also @ topfuel. I have never gotten mould in my setup and my temps are alot hotter then most peoples due to living downunder

shaun2000 said:

lol. You say using co2 is a waste of money and yet you tell us you use a water cooled geni.

To be honest i use it and get double yields.

For the method to work u dont just use yeast and water. That will do nothing and smell rank
You need sugar.

What i do is buy a 3 liter bottle of apple juice (no preservitives , they stuff up the yeast cultures) And then i add 2 cups of sugar and half a capful (very smal cap half a teaspoon) Of breweing yeast , then i put a slow realese pressure cap on and then i give it a nice shake and place it in my grow chamber. It will take about a day To activate.. Then i can ethier leave it in for up to a month (toppping up the sugar lvls every week) Or And this is what i have been doing latly, is i Take it out after 3-5days and Get drunk off it. and i add more.

Oh i also use one per plant.

total cost is around 15 bucks for the yeast and caps (that lasted me almost a year) and 3 dollers per drink. (very cheap IMO)


Also as a side note. Hydro will always produce more from the same strain with a competent grower and using the same system. Also In hydro the water plays a much bigger part as you Will be having Higher nutrient lvls and faster absorption rates.



Also . With the mold issues. Id be checking my humidity first.

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overall yeast is a waste of money. buy a generator or tanks and it will by far make up for it. buy a ppm meter and find out how pathetic the co2 is from yeast LOL. even the hydro shops at least the honest ones will tell you yeast is a waste of money. my friend used to do it until i let him borrow my spare ppm meter. how do u know it's getting you double yields? did u have 2 rooms with exact conditions except the co2 variable? or are you just feeding/water better on this grow. that will probably explain your double yield. sorry but you will never know how much it is helping unless you are able to measure your ppms. dont you have a friend that will let borrow one? really though its like come on, you have money to grow pot but

keeping humidity level low is important, but sometimes no matter how low your humidity is, you can get mildew. you can have 20% humidity with a very clean room and still get mildew if your dark temps are too low. even on highly resistant strains. this was happening to a friend of mine and we it stopped after putting his night temps from 65 to 75F. 70 we still had problems. his day temps we go 85F. hes got co2 tanks and we go 1800 ppms at his place. we all laugh at the cheap ideas ppl come up with for growing.

theres a reason why us serious growers spend a lot of money. we like to try everything. we know what works best and what doesnt and usually you get what you you pay for. good friend of mine tried going cheap with his setup. lets just say that he's found a new hobby less expensive than growing after seeing our high tech advanced setups far superior to these amateurs out there on the net praising yeast for co2.