CO2 enrichment.

I currently have a 4x4 tent that I am growing in. I recently put a 1000w into it and my temps are 82-84 with lights on. It has an air cooled light. I have a room A/C in the room and the room is only for my growing. I am considering running CO2. I know there are basically 3 ways I can do this. I can easily put a plywood partition around my room AC and put the dehumidifier in there too with the CO2 setup. This will make my grow room completely enclosed and controlled. My options as far as I know are:

1) Generator.
2) CO2 bottle with regulator.
3) Making it with yeast and sugar.

Yeast method: I have experience as a brewer, so I can probably do it with yeast without any outlay in cash and relatively easily. (30 gallon garbage can and 20 pounds of sugar to start) I can do it and actually get the CO2 levels to where I want them. It helps that sugar is easy to get and no one is going to question it. I can also regulate this fairly easily. Also, I can get drunk with the alcohol afterwards. Have any of you seen someone do it with yeast and do it correctly? I haven't. I know it can be done since I regularly saved CO2 from my brewing to dispense the kegs. I have been doodling a little and checking math, and I have approximate #s for it.

CO2 bottle w/ regulator: I have connections with homebrewing people, so I already know where to get co2 tanks and they know I brew so no questions asked or suspicion.. I have regulators and I could probably make something to regulate CO2 with what I have, but I can just buy one for pretty cheap just for the purpose. I know there are more expensive and better controllers than the 50 dollar ones online, but on a 12 hour on 12 hour off timer and with calculations done I technically don't need a PPM CO2 meter right?

Generator: Probably more than I need, and I can't imagine the heat and LP gas would be any cheaper than the bottles.

My goals with using CO2:

Increase my yield.
Make 85-90 degrees an ideal temperature.
Increase yield.



Does anyone have anything to add to this? Is there something I am overlooking?


Are there any options I am missing?

When Im done making Dry ice kief, I put the dry ice in a container with holes in it and put it in the growroom for Co2. Thats the only option I could think of that you are missing.

Dank Hands said:

When Im done making Dry ice kief, I put the dry ice in a container with holes in it and put it in the growroom for Co2. Thats the only option I could think of that you are missing.

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I considered that, actually. The price was pretty high compared to what yeast and tanks would be I think. I figured a cooler with a hole in the lid would work for dry ice.

Would a simply injector/regulator + CO2 tank with a CAP PPM-4 monitor be everything I needed to do enrichment?

For a good boost use ExHale bags. They are around 35 buck but last between 6 and 9 mounths. And all you do is place them above your plants and let it do it's thing. I have air cooled hoods so I just place them on top and leave. I also use a tank but I'm sealed so no air going out or in. That's a whole different story. But when I had a 4x4 tent I used 2 and never worryed. Won't give you the 1500 ppm but will be better then normal air and cheeper then tanks and gens. And you don't have to clean up that baking soda mess.

Hey Cathoris, have you checked out this thread? It's about aerobic CO2 production with yeast:

https://www.rollitup.org/do-yourself/162265-co2-via-yeast-right-way.html

As a brewer, this is probably more intuitive for you than for me, but if it seems viable, I'd love to get your feedback because I'm trying to set something like this up. I have no brewing experience whatsoever...zero. So I'm not sure about ratios, amounts equipment, construction or anything. Maybe you'd know what to do though.

Redoctober said:

Hey Cathoris, have you checked out this thread? It's about aerobic CO2 production with yeast:

https://www.rollitup.org/do-yourself/162265-co2-via-yeast-right-way.html

As a brewer, this is probably more intuitive for you than for me, but if it seems viable, I'd love to get your feedback because I'm trying to set something like this up. I have no brewing experience whatsoever...zero. So I'm not sure about ratios, amounts equipment, construction or anything. Maybe you'd know what to do though.

Click to expand...

That link has a lot of information, but most of it is close to useless. Not because the author doesn't know about yeast, but in so far as you have a lot of variables. He is using math to guess. There are hundreds if not thousands of types of common yeasts. You don't need to play with the ph of your yeast/co2 setup. If you want to do it without complicating issues, this is what you should do.

1) Get a 5 gallon bucket with a lid or a 30 gallon garbage can, depending on how big you want it. Sanitize it with bleach and water.

2) You need an airlock. Why? To prevent contamination of the yeast and to show you that CO2 is still being produced by watching for bubbles. The simplest way to make one would involve taking a 2liter soda bottle, cutting 2 holes in it for fish tank air tube, run one end into the grow and one end into the bucket. That is really all you need for hardware. You can buy a fishtank one for like 2 bucks on ebay or make the one I was talking about, heres a picture:


Do you see how the hose comes out of the yeast bucket,goes into the 2 liter then out and into the grow? See how the 2 liter is full of water? You will be able to just glance at the 2 liter and see if CO2 is still being made.

3) Mix sugar, water, yeast, and yeast nutrient in the bucket. If you wanted to make wine you could just put a bunch of fruit juice in the bucket. Aim for about 3 gallons of the 5 gallon bucket filled as some yeasts have explosive fermentation and you could very easily blow yeast and liquid out the top of the bucket and all over your room. There are math equations to calculate how much of each and ect ect. In the home it is impossible to know the information needed to actually use the math equation for anything more than the slightest guess.

How much should you use? If you want the numbers, I will post them but unless you like doing math there is no point since they don't make you any more accurate. 2 1/2 pounds of sugar per gallon of water is the magic number. You mix the sugar, water, yeast, and yeast nutrient(or fruit if your making wine) together, pop the lid on and just leave it alone until it stops bubbling or slows a lot.

If you are doing a tent, you can use a 5 gallon bucket and just empty out most of the contents when it stops bubbling. 5-7 days mostly. Leave about a gallon of the old yeast/liquid in the bottom that way you don't have to use more yeast and it will start back up faster. If you are doing a whole room you will have to use a kitchen garbage can or something larger. If you use a kitchen garbage can you can add a gallon of sugar water every couple days and not have to clean it out as much. A 4x4 tent only needs about 1/4 of a pound of sugar fermented a day, a 10x10 bedroom would probably need a pound give or take.

Everything is a rough estimate on my part because exact numbers are not possible. The temperature, size, how many items are in the room, your exhaust, and all of that are going to change it. The numbers I gave will get you in the ballpark of where you need to be.

When I made the picture I showed both lines going down into the 2 liter bottle. This is incorrect, you only need the one from the bucket down in the water, the other needs to be in the air.

Thanks for the breakdown Cathoris. I think I understand what is going on, but since I am a total noob when it comes to yeast, I'm going to take this one step at a time. I basically would like to supplement a 10x10 room like you said. I don't know how many 5 gallon buckets this will take or if it's even possible to calculate but I guess I'll find out. So for the first step, I will take a Home Depot 5 gal bucket and drill out 2 holes for tubing. One hole for the tube that will feed the room at large and the other for a tube going into a bottle with water to use as an indicator correct?

Now when I am mixing the yeast in the bucket, how much yeast do I use? I've never bought yeast before other than at the supermarket in those little packets it comes in for making dough. Can I use that type of yeast? Or do I have to find a brew store and get special yeast?

So then I mix 2.5 lbs refined white sugar from the supermarket per gallon of water? Which would be 7.5 lbs sugar and 3 gallons water and a can of tomato paste or something for food. I'm not sure if home depot bucket lids form an air tight seal, but would this be necessary?

I am assuming that this method is fermentation i.e. anaerobic, unlike the aerobic method in the other thread, is that correct? (I was hoping to try the aerobic method because according to the other thread, it produces 3x as much CO2 as fermentation. I seems that the only real difference is that in the aerobic method, you aerate the mixture with an air stone when you first dump the yeast in.) Then in approx 5-7 days, I would just pour off 2 of the 3 gallons and simply add another 2 gallons of water, 5 lbs sugar, and another can of tomato paste, no more yeast? Do you recommend anything else besides tomato paste for a food source?

In my opinion without a CO2 controller, you can regulate your environment enough to take full advantage of the CO2 generated (you also want to regulate temps based on CO2 levels). Not saying putting a co2 bag or yeast won't possibly increase yields, however it might not, and you could spend that money elsewhere. The one exception is if you use tanks, you can calculate room volume to figure out how much to use.

In regard to cost of LP/NG to the cost of tanks, I've done the math, and LP burner is about 1/4 the cost of tanks, and NG is 1/16th the cost. This was done with my local costs, which are probably about average. However tanks are heavy, and require alot of trips. LP can be filled at home depot and such 24/7. If NG is an option thats the way to go.

I personally use a water cooled (hot water tank) with a controller. Its so cheap and stays so cool I don't even worry about waste. The set up is also significantly cheaper than a burner. I don't know any circumstance where I would reccomend a normal burner to anyone anymore, unless they live in an always cold climate or something and need to bring temps up all year.

Use a generator - doesn't have to be a store bought one, anything that burns gas / propane will work. You can even use fireplaces and hot water heaters.

You really should have a controller - haven't found a way to DIY one, Titan makes a good one for $399 though (there are cheaper, but the Titan one is really nice)

If you have some time to play, and are able to borrow a controller, you can use a timer and a generator and get close to the right co2. My buddy leaves a 22,000btu fireplace run 24/7 in his basement and it keeps the co2 between 1400-2200 ppm (builds up in the day, drops when the plants start using it) Problem is, you need a monitor in the beginning to see what your room will take, and you need to have plants going when you do, because the plants will greatly affect your numbers.


If it's an option, put the co2 generator in a nearby room and duct in the co2. Roxul is a type of mineral wool insulation that is sold in thick sheets, you can use it as an extra layer of fireproofing if needed.

Also, yeast bottles are crap. The problem is, the only people who ever do them are broke, which means they don't have $300 for a co2 monitor to see that they aren't doing anything.

Large vats of fermenting sugar will draw, among other things, gnats. If you really wanted a super low cost way of making small amounts of co2, with no way to monitor it, you'd be better going to walmart and getting a Colman cooking stove, or running a gas oven, or going to the basement and unhooking a vent pipe on a gas hot water heater.

w/ your temps, it would be a problem but you can burn rubbing alcohol. Many yrs ago I found a formula & at the time,I had a 4x4x7 box in an unheated barn so for winter,heat didn't mater. a little over an oz burned over 12hrs was needed to bring that sized room up to 1200 ppm according to the formula.I had a small lamp that would burn about 2 oz over 10-11 hrs. I figured close enough since I wasn't sealed very well. it did make a difference.never bought a CO2 meter to confirm.

I have considered starting a sealed room. looking at about 4x6. anyone have any idea how long a 20# tank would last?

in researching a sealed room I found this for any looking for a cheep CO2 controller.
http://www.co2meter.com/collections/co2-sensors/products/k-30-co2-sensor-module
$125. it has 2 analog outputs that can be custom configured.I have thought about setting 1 for on until 1200ppm to trip a relay for the solenoid and the other to read out in volts so I could have a visual indicator of the current levels.

Redoctober said:

Thanks for the breakdown Cathoris. I think I understand what is going on, but since I am a total noob when it comes to yeast, I'm going to take this one step at a time. I basically would like to supplement a 10x10 room like you said. I don't know how many 5 gallon buckets this will take or if it's even possible to calculate but I guess I'll find out. So for the first step, I will take a Home Depot 5 gal bucket and drill out 2 holes for tubing. One hole for the tube that will feed the room at large and the other for a tube going into a bottle with water to use as an indicator correct?

Now when I am mixing the yeast in the bucket, how much yeast do I use? I've never bought yeast before other than at the supermarket in those little packets it comes in for making dough. Can I use that type of yeast? Or do I have to find a brew store and get special yeast?

So then I mix 2.5 lbs refined white sugar from the supermarket per gallon of water? Which would be 7.5 lbs sugar and 3 gallons water and a can of tomato paste or something for food. I'm not sure if home depot bucket lids form an air tight seal, but would this be necessary?

I am assuming that this method is fermentation i.e. anaerobic, unlike the aerobic method in the other thread, is that correct? (I was hoping to try the aerobic method because according to the other thread, it produces 3x as much CO2 as fermentation. I seems that the only real difference is that in the aerobic method, you aerate the mixture with an air stone when you first dump the yeast in.) Then in approx 5-7 days, I would just pour off 2 of the 3 gallons and simply add another 2 gallons of water, 5 lbs sugar, and another can of tomato paste, no more yeast? Do you recommend anything else besides tomato paste for a food source?

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You could use fruit juice. Then you could drink the resulting liquid after it stops bubbling. Free booze. Potatoes would work. The russians make a potato beer. You could just by some malted barley also. Any kind of grain or fruit would work.

Yeast multiplies. One packets may take a day or two to start bubbling, but even a teaspoon will get 100 gallons to ferment eventually. Buy a single packet on ebay for $1-2. Wine or champagne yeast. More or less when you throw the yeast in they will multiply until they completely control the container, then they will start turning sugar to alcohol. The higher the max alcohol content of your yeast the longer it will work without having to be changed out. You can make a yeast starter if you want which is essentially just putting the yeast in a cup of luke warm water with some sugar. It will get frothy almost immediately, let it sit for a hour or two then pour it in to the bucket. It will help to get the yeast mobilized quicker.

roidrage152 said:

In my opinion without a CO2 controller, you can regulate your environment enough to take full advantage of the CO2 generated (you also want to regulate temps based on CO2 levels). Not saying putting a co2 bag or yeast won't possibly increase yields, however it might not, and you could spend that money elsewhere. The one exception is if you use tanks, you can calculate room volume to figure out how much to use.

In regard to cost of LP/NG to the cost of tanks, I've done the math, and LP burner is about 1/4 the cost of tanks, and NG is 1/16th the cost. This was done with my local costs, which are probably about average. However tanks are heavy, and require alot of trips. LP can be filled at home depot and such 24/7. If NG is an option thats the way to go.

I personally use a water cooled (hot water tank) with a controller. Its so cheap and stays so cool I don't even worry about waste. The set up is also significantly cheaper than a burner. I don't know any circumstance where I would reccomend a normal burner to anyone anymore, unless they live in an always cold climate or something and need to bring temps up all year.

Click to expand...

I went with CO2 and a controller. Total cost was about 425 dollars. However, I could of done it for under 200. Calculating the CO2 output of yeast or a bottle without a controller will get you in the ballpark. It will be better than growing without either way. Turning my CO2 in the bottle on a timer for 15 minutes once every 3 hours kept my co2 levels about 8-900 average without a controller. For the cost of a controller you could refill a co2 tank 10 times. That means it would be 10 grows before I would even break even on buying the controller. I still bought one though

tibberous said:

Also, yeast bottles are crap. The problem is, the only people who ever do them are broke, which means they don't have $300 for a co2 monitor to see that they aren't doing anything.

Large vats of fermenting sugar will draw, among other things, gnats. If you really wanted a super low cost way of making small amounts of co2, with no way to monitor it, you'd be better going to walmart and getting a Colman cooking stove, or running a gas oven, or going to the basement and unhooking a vent pipe on a gas hot water heater.

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Just because most people who use them don't do it right doesn't mean it can't be effective. I am into brewing, so I went ahead and bought a kegerator for 100 bucks with co2 bottle. If I had access to a CO2 controller I could borrow, I would of borrowed it, calibrated my grow, and then gave it back instead of buying one. After I finish this grow I am going to use yeast and do a test. I have a PPM-3 CAP controller. I will put the yeast solution in 5 gallon corny kegs and then output it through the CO2 regulator/controller I have and use the PPM-3 cap to do it. The yeast will easily build up pressure inside the of the corny kegs and it will hold high pressure. I have used the waste co2 from brewing to then pour the kegs that made the co2.



The gnats thing is incorrect. I have been brewing for years and I have never had gnats near my beer, wine, or sugar water while fermenting.

Thanks Cathoris! I never thought about the aspect of turning on or shutting off the CO2 coming from the bucket. I'm not even sure how that could be done. I kind of always assumed that the bucket method wouldn't really get the CO2 up to crazy levels anyway, so it wouldn't really be a concern. The issue would always be too little CO2 and not too much. So the yeast from the supermarket is really not very good to use then? What I've seen on amazon looks similar to stuff I found at Whole Foods or Mrs. Greens. Would this work? http://www.amazon.com/Packs-Lalvin-Dried-EC-1118/dp/B003TOEEFG/ref=sr_1_4?ie=UTF8&qid=1328959213&sr=8-4

roidrage, I'm not sure what LP and NG are? Natural Gas? What is a water cooled hot water tank? Isn't that an oxymoron lol? I do agree that Propane or a CO2 tank are the most efficient methods for CO2 generation, but they are headaches in their own right. I know that the technology is pretty well worked out, but I'm not particularly in love with the idea of burning off propane gas inside, especially when I'm not there. I know thousands of people do it every day, but it makes me nervous. CO2 tanks are now a watched item by the feds. I had my local hydro guy advise me against it because a few customers of his told him stories about getting questioned by LE for filling up a little too frequently at their local shops. Hearing that pretty much put me off the whole tank business, not to mention the fact that lugging that thing back and forth every week would get pretty annoying. If the yeast method falls flat on its face then maybe I'll consider some other possibilities, but it seems viable in theory anyway. I will be using a CO2 monitor, not a controller, so I will at least be able to gauge the output and adjust accordingly. It may require 5x5 gallon buckets to raise the CO2 level appreciably, but I'm fine with that. It really doesn't seem like that big of a hassle.

I once bought a propane burner at home depot when the power went out in the dead of winter and there was no heat. It did heat the place up, but the fumes were absolutely noxious and completely unsafe to breathe. I felt it in my lungs and throat for a day or two afterwards. In fact it warns on the label to never burn it in an enclosed space, and I can see why. I don't know what the difference is between a $400 propane burner from a grow store and the $50 one I had, but I can't imagine being anywhere near one of those things when it is burning off propane! It's the same process in both cases so I'm baffled. I think this was the one I had: http://www.amazon.com/Variable-Certified-Propane-Tank-Heater/dp/B004ST3RUO

Basicaly the water cooled co2 Gen is a hot water heater. Hydrogen is the company that first marketed them that I know of, however, people figured out it was just a chinese portal hot water heater. Unlike a normal CO2 burner, which is basically like several bunsen burners in a box, the hot water heater basically cools itself by running the water through it. I think its supposed to be 87% efficient at cooling or something like that. Here is the thread I spent a day reading before doing all my research, but I think my CO2 probably costs like $20-30 a month and I fill a 12x12x10ft root to 1500ppm 12 hours a day, and also vent that to my veg room 10ft away. I also don't recirculate my water, i run it to waste.

https://www.rollitup.org/advanced-marijuana-cultivation/410850-well-n-tankless-water-heater.html

roidrage152 said:

Basicaly the water cooled co2 Gen is a hot water heater. Hydrogen is the company that first marketed them that I know of, however, people figured out it was just a chinese portal hot water heater. Unlike a normal CO2 burner, which is basically like several bunsen burners in a box, the hot water heater basically cools itself by running the water through it. I think its supposed to be 87% efficient at cooling or something like that. Here is the thread I spent a day reading before doing all my research, but I think my CO2 probably costs like $20-30 a month and I fill a 12x12x10ft root to 1500ppm 12 hours a day, and also vent that to my veg room 10ft away. I also don't recirculate my water, i run it to waste. https://www.rollitup.org/advanced-marijuana-cultivation/410850-well-n-tankless-water-heater.html

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Very nice roidrage! Are you running an identical setup to legallyflying in that thread? Water tank outside with sump pump and natural gas lines? So as I understand it, the water gets pumped out of the barrel and into the little heater unit where gas is burned and heats the flowing water somehow (I'm a little clueless on this part about how the water actually gets heated), then the burned gas is converted to CO2 which fills the room, and the water simply flows back out to the barrel. Do I have that right? That's a nifty little setup. I'm not sure what it takes to run gas lines and if you need a professional to do that, but otherwise it looks like a pretty doable project.

Redoctober said:

Thanks Cathoris! I never thought about the aspect of turning on or shutting off the CO2 coming from the bucket. I'm not even sure how that could be done. I kind of always assumed that the bucket method wouldn't really get the CO2 up to crazy levels anyway, so it wouldn't really be a concern. The issue would always be too little CO2 and not too much. So the yeast from the supermarket is really not very good to use then? What I've seen on amazon looks similar to stuff I found at Whole Foods or Mrs. Greens. Would this work? http://www.amazon.com/Packs-Lalvin-Dried-EC-1118/dp/B003TOEEFG/ref=sr_1_4?ie=UTF8&qid=1328959213&sr=8-4

Click to expand...

Yep, that is champagne yeast. 1 pack is all you need regardless of how big your tank is. More won't hurt though. To turn off CO2 from yeast you will require a tank that seals. I use these in brewing:


It is called a Corny(cornelius) keg. It was used by pepsi to store soda until they came out with the soda syrup in a bag deal. It is good to a high pressure and has a safety vent if the pressure gets too high. It would be extremely easy to set this up to a co2 regulator and co2 controller. It would not need an air lock or anything. The yeast aren't affected by the pressures involved. Personally I would use 2 just to make sure that no beer/yeast/wine/sugarwater was forced up to the top of the tank by the yeast fermenting. Sometimes they get really excited and overflow. By using 2 you would be able to use the second as an overflow basically. You could also just put 4 gallons of liquid in the container I did this when I brewed more. Id brew in 1 keg, and save the CO2 in the other. Then once I put the keg into the kegerator I would use the one where I saved the CO2 to dispense the beer. It kept me from having to refill my CO2 tanks.

I might add that since it would still require a regulator and controller that cost 250-350 dollars. Corny kegs are 40 dollars used give or take. It wouldn't be saving you any money at this point in all honesty unless you like to drink a lot. It costs about 25 bucks to make 5 gallons of guinness type beer or sierra nevada IPA type beer. That would give you CO2 for 4-5 days. You get about 50-55 beers from 5 gallons. If you spend 25 bucks a week on beer it would basically be free CO2. I know there are times when I spend many hundreds of dollars a week on beer, but that might only be 15-20 beers of the kind I drink. Making a sugar/juice based wine would be significantly cheaper. 5-10 per 5 gallon batch. If you have fruit trees or access to one then you could easily cut the cost down to a couple dollars a week. With wine you could add the sugar in 2 batches and extend it for 10-14 days.