co2 Help

I am just going to use the regulator because of the heat issues associated with burning the gas though I weighed both options.

It appears the regulator is going to cost me about $150, and the tank $230, filled... and I will need to fill that bitch up once a week - not exactly a cheap investment but I think i'll get an extra boost to more than pay that off in a single cycle.


$380 to get started without a c02 controller. With the c02 controller I'm looking at more like $880....really starting to think I should just find a friend who will lend me $500 to get the brain so I know it's being done effectly.

The c02 calculators online tell me it will take 26 minutes to fill my room to 1500PPM of c02. I would then try to leave the lights off for as long as I could to let it absord before putting exhaust back on. I figured this made sense, right?

My other friend told me ideally you want the 1500PPM to be constant... which is basicly what the brain would do for you. If the temps in room go up too much, c02 is cut...exhaust on. If not enough c02 in the air, exhaust off, c02 on. It sounds wonderful to be able to have a great efficient way to run the c02 but I'm not 100% sure I can afford the 500 bucks for a controller right now.

Like I said, my friend said he would be willing to come over with the brain..hook it up and leave it there for a few hours so I can get a grasp of how quickly the c02 is leaving the room when the exhaust fires back up, and I can mathmatically try to figure out the optimal poor man's version of c02.

Would fillng the room for a half hour every hour and then letting them absorb the c02 with the exhaust off, and then bam put the exhaust fan back on. Would this work?

From what I understand from him the room needs to stay more constant than like that. I know people out there use c02 methods without the expensive controller, I'm curious how you approached it.

You could use those analog timers to do 15 minute stints, but those sometimes aren't too accurate, especially if you loser power for any small amount of time.

My room is sealed for the most part, there's bent wood from the door being a bit weathered from a few years of growing in here, but I put a foam strip along the door in all places I could.

Thanks again everyone, keep this conversation open. I'm trying to figure out if I can do this WITHOUT the c02 controller for the first run through, and buying one later on... or if I'm just gonna waste my time using the c02 calculations online and combine that data with what I get from my boy's controller.

DR. VonDankenstine said:

Most regulators have a SCFH-setting. For your size room I would just set it to 1.5scfh and have it kick off when you run your fans---you only need to run it an hour after lights on and turn off an hour before lights out.------I would recommend sealing the room and running passive light cooling then you don't have to vent your room during the lights on period and you run your exhaust during the lights out which is even better because you will lower your humidity at night. Spent the money and get an co2 controller-------DO NOT GET THE CAP PPM4----HPS BALLIST NOISE WILL FREEZE THE UNIT UP ALL THE TIME. CAP doesn't care and will not replace or back the units once you purchase them.

Click to expand...

I'm either not understanding what you are talking, or don't think it would work... can't figure out which.

If we only air cooled our lights while the co2 was on, sure that would help with temps...I'm guessing that's why you would do that. As for only exhausting when the lights are out, well my room is gonna get just too damn hot if that's what i did. Maybe I'm confused about something you are trying to explain.

Here is what I know
-my room is 960 cubic feet.
-when I run my co2 I want the exhaust off so I can fill my room with 1500PPM of c02.
-the calculator told me it would take 23 minutes to do.

Questions about where to go from here:
-the exhaust should be left off for a little while AFTER you let the gas out so they can absorb it well. I figured maybe 10 minutes?
-by the end of that 10 minutes I'm guessing my c02 levels would decrease as plants absorb it, and then when I kick the fans back on obviously most of the c02 will be shot out of the room.
-at that point I would assume our c02 level would think be back to our atmosphere;s level...right around 300...maybe a bit higher.
-I would repeat the same prcoess twelve times while lights are on.

This would mean they received c02 for the 26 minutes the pump was on, and then when c02 turns off we likely hit our 1500 pppm. the ladies then get to enjoy the rays, sway in the wind, and perhaps eat some icecream for the next ten minutes while the c02 is no longer on, and neither is exhaust. They simply sit back, relax, and enjoy the goodies I'm giving them.

Now after that, my fans come back on and clear the c02 outta the air almost immediately I would guess. So we just had 36 minutes of out the hour that they were receiving gas with no interuptions from ventlation. I would then ventilate for 24 minutes...and start cycle over.

It seems like it could work just fine but my c02 LEVELS won't be held around 1500. I still have to think they would benefit from the 36 minutes of c02 enriched air rather than getting only what they get from the atmosphere.

Any and all help is really appreciated.. you guys are helpin. Sorry if I seem like a noob with c02, but I AM!!!

I'm sure its worth the frustration trying to figure out how to do it, and also the money... in the end I should notice a nice difference in yield.

You are over-thinking it!!!---keep it simple. Why is your room so hot when your lights are out?????----What kind of light system are you using? Did you know that your temps should be higher when using co2? like 83-85...Did you know that they make a water cooled co2 generator that can run off propane or natural gas. There are good ways to go about using co2----one of the worst ways is blowing it out your exhaust. Sometimes you have to rethink your room but in the long run if your going to run bottled co2 it's a needed. I've helped someone who Had a 1440 CF room and when it was all said and done his was burning a 20 pound tank every 8 days.(that's great for that size room).----sealed room/passive lights/fuzzy logic controller and no venting during co2 enrichment hours(10hrs@1500). Also your co2 ppm's should match your nutr ppm's @83deg for optimal absorption.

If everything is perfect------air/light/co2/temps/medium/water/air around plants/plants health, you could get a 20% gain. I would count on getting about 10% gains over not using the juice.

#1
08-13-2008, 02:18 AM
DR. VonDankenstine
Stoner
Mr. Ganja



*** water cooled co2 generator ***
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i will most deff. get flamed for my suggestion but the cheapest way to fill your room with c02 without getting tecnical is to fill up a gallon jug with water sugar and yeast. and let it ferment for two weeks in your grow room 4 jugs in a room your size will get it done.every two weeks refill the jugs.laugh if you want but it works.And its allmost impossible to over do it.it smells kinda like beer in your grow room but its easy to adjust to. and no need to adjust venting timer cause for the 12 hrs the lights and vents are off your plants are absorbing the c02 un interrupted.yes they get less c02 from the jugs but they get it for a verry extended period of time.i ve said my peace so fire away

DR. VonDankenstine said:

Most regulators have a SCFH-setting. For your size room I would just set it to 1.5scfh and have it kick off when you run your fans---you only need to run it an hour after lights on and turn off an hour before lights out.------I would recommend sealing the room and running passive light cooling then you don't have to vent your room during the lights on period and you run your exhaust during the lights out which is even better because you will lower your humidity at night. Spent the money and get an co2 controller-------DO NOT GET THE CAP PPM4----HPS BALLIST NOISE WILL FREEZE THE UNIT UP ALL THE TIME. CAP doesn't care and will not replace or back the units once you purchase them.

Click to expand...

Agreed! The units are shit! But the counter works. CAP replaced mine no questions asked, but the 'new' rebuild one they gave me is shit as well.lol.
Dr. You are being kind to the CAP unit when you say the ballast freezes them up , since I have a digi balast that is outside my grow. I think the unit has serious program issues.

McGruppsMonsters said:

I'm either not understanding what you are talking, or don't think it would work... can't figure out which.

If we only air cooled our lights while the co2 was on, sure that would help with temps...I'm guessing that's why you would do that. As for only exhausting when the lights are out, well my room is gonna get just too damn hot if that's what i did. Maybe I'm confused about something you are trying to explain.

Here is what I know
-my room is 960 cubic feet.
-when I run my co2 I want the exhaust off so I can fill my room with 1500PPM of c02.
-the calculator told me it would take 23 minutes to do.

Questions about where to go from here:
-the exhaust should be left off for a little while AFTER you let the gas out so they can absorb it well. I figured maybe 10 minutes?
-by the end of that 10 minutes I'm guessing my c02 levels would decrease as plants absorb it, and then when I kick the fans back on obviously most of the c02 will be shot out of the room.
-at that point I would assume our c02 level would think be back to our atmosphere;s level...right around 300...maybe a bit higher.
-I would repeat the same prcoess twelve times while lights are on.

This would mean they received c02 for the 26 minutes the pump was on, and then when c02 turns off we likely hit our 1500 pppm. the ladies then get to enjoy the rays, sway in the wind, and perhaps eat some icecream for the next ten minutes while the c02 is no longer on, and neither is exhaust. They simply sit back, relax, and enjoy the goodies I'm giving them.

Now after that, my fans come back on and clear the c02 outta the air almost immediately I would guess. So we just had 36 minutes of out the hour that they were receiving gas with no interuptions from ventlation. I would then ventilate for 24 minutes...and start cycle over.
I don't think that is sufficient.

It seems like it could work just fine but my c02 LEVELS won't be held around 1500. I still have to think they would benefit from the 36 minutes of c02 enriched air rather than getting only what they get from the atmosphere.
You are shooting in the dark without the counter, imagine someone getting meds through a drip without a counter

Any and all help is really appreciated.. you guys are helpin. Sorry if I seem like a noob with c02, but I AM!!!

I'm sure its worth the frustration trying to figure out how to do it, and also the money... in the end I should notice a nice difference in yield.
The difference will be in bud quality, not yield The nugs are tight

Click to expand...

You WILL need AC mate!!! to run co2 efficiently
I tried sooooo hard building a new space as efficiently as possible. I mean cool tube, insulation on the outside of the light etc. Man my light cools so well my hand doesn't even get warm when I leave it on the glass. NO CHANCE, the radiation heat just builds up in the space. I fought the ac for a long time but now I would NEVER go back! Not in my climate at least ( SoCal)

Here is something to think about. My best bud has and identical grow size as mine (3x3x7) except no ac and he vents (4" 100cfm) continuously. In order to maintain co2 levels at 1400ppm he has to have the regulator set at 1.7 the entire lights on time! That means a refill every 5 days. My space is sealed with ac and I need a refill every 3-4 weeks. I pay 20-30 bucks a month he pays 80-100 bucks. Keep in mind my plants have a perfect enviro with ac, his plants get hot as hell. Ley's not even start on humidity without ac....

Listen, the reason I brought up the CAP re-builds is that the counter works great on them and the rest you can adjust with the regulator. Only 200 bucks. That's what I do right now. It's no big deal, mine runs on a constant on .3 setting. You check it once a day to make sure it stays within your set range and that's it. I like it almost better, cause I am not worried anymore about killing my plants with an over or under dose,lol!

Another point to consider: The AC costs me under $30 a month and it eliminates the need for additional venting during lights on. I save $80 from the sealed room (co2 refills). IT's a 'no brainer'!

Good luck!

What do you think Doc?

unity said:

You WILL need AC mate!!! to run co2 efficiently
I tried sooooo hard building a new space as efficiently as possible. I mean cool tube, insulation on the outside of the light etc. Man my light cools so well my hand doesn't even get warm when I leave it on the glass. NO CHANCE, the radiation heat just builds up in the space. I fought the ac for a long time but now I would NEVER go back! Not in my climate at least ( SoCal)

Here is something to think about. My best bud has and identical grow size as mine (3x3x7) except no ac and he vents (4" 100cfm) continuously. In order to maintain co2 levels at 1400ppm he has to have the regulator set at 1.7 the entire lights on time! That means a refill every 5 days. My space is sealed with ac and I need a refill every 3-4 weeks. I pay 20-30 bucks a month he pays 80-100 bucks. Keep in mind my plants have a perfect enviro with ac, his plants get hot as hell. Ley's not even start on humidity without ac....

Listen, the reason I brought up the CAP re-builds is that the counter works great on them and the rest you can adjust with the regulator. Only 200 bucks. That's what I do right now. It's no big deal, mine runs on a constant on .3 setting. You check it once a day to make sure it stays within your set range and that's it. I like it almost better, cause I am not worried anymore about killing my plants with an over or under dose,lol!

Another point to consider: The AC costs me under $30 a month and it eliminates the need for additional venting during lights on. I save $80 from the sealed room (co2 refills). IT's a 'no brainer'!

Good luck!

What do you think Doc?

Click to expand...

Sounds great to me!!!---I run tanks in the summer and gas in the winter---I keep my temps around 83 when the juice is on.-----You must run a scrubber in your room if your using A/C and venting the heat to the outside otherwise your just dumping the dank smelling air outside for all to appreciate. I have a portable A/C unit but never use it(thought I was going too). It has a 4" exhaust hose that I rigged up with a small ozone generator and I wired a digital controller to kick the ozone on for 4mins before the A/C cycles, I have never really had the chance to test it out--been messing around with some really small cab grows. I like the idea of the water cooled generator. And the people I have talked to say they work well and give off very little heat.

unity said:

Agreed! The units are shit! But the counter works. CAP replaced mine no questions asked, but the 'new' rebuild one they gave me is shit as well.lol.
Dr. You are being kind to the CAP unit when you say the ballast freezes them up , since I have a digi balast that is outside my grow. I think the unit has serious program issues.

Click to expand...

A Lot of users of the ppm4 have experienced lockout and freeze---I was told by cap reps this was due to the frequency signal giving off of digital ballasts ---they also said the fuzzy logic model could do the same but less often. They wanted to charge me a 180 restocking fee plus the difference of the 2 models. Anyway they should at the least post the warning on all the controller boxes to let digital ballast owners know about the problem.

Unity Said:"Here is something to think about. My best bud has and identical grow size as mine (3x3x7) except no ac and he vents (4" 100cfm) continuously. In order to maintain co2 levels at 1400ppm he has to have the regulator set at 1.7 the entire lights on time! That means a refill every 5 days. My space is sealed with ac and I need a refill every 3-4 weeks. I pay 20-30 bucks a month he pays 80-100 bucks. Keep in mind my plants have a perfect enviro with ac, his plants get hot as hell. Ley's not even start on humidity without ac...."

I live in a more moderate climate than SoCal, so I'm not 100% sure I will need it... but I could be wrong. Like I said, I can turn all fans off for over 30 minutes before the temps go over 85 degrees. I figured that meant my room was cooled enough?

I run an eight inch exhaust, and 6 inch bringing fresh air in. So far, so good... and colder months approach shortly... only another 3-4 weeks of the warm weather we are currently experiencing.

DrVon Said:"You are over-thinking it!!!---keep it simple. Why is your room so hot when your lights are out?????----What kind of light system are you using? Did you know that your temps should be higher when using co2? like 83-85...Did you know that they make a water cooled co2 generator that can run off propane or natural gas. There are good ways to go about using co2----one of the worst ways is blowing it out your exhaust. Sometimes you have to rethink your room but in the long run if your going to run bottled co2 it's a needed. I've helped someone who Had a 1440 CF room and when it was all said and done his was burning a 20 pound tank every 8 days.(that's great for that size room).----sealed room/passive lights/fuzzy logic controller and no venting during co2 enrichment hours(10hrs@1500). Also your co2 ppm's should match your nutr ppm's @83deg for optimal absorption."

Maybe we aren't communicating correctly here, I do apologize if I'm not speaking effectively. My room is *not* too warm... with the lights out I run at about 72 with my d\h on.

Lights on, it runs at about 77 or 78.... I posted earlier I can leave my air cooled\exhaust fans off for over a half hour before it gets to 85 in the canopy and we're in the warm part of the year where I live. My temps aren't a ton of concern for me.

As for using the generator to burn the gas, my room mates and I have both decided we would just feel more comfortable with the regulator instead of burning the gas, even if it means an extra 20-30 bucks a month. Are you saying you think burning the gas over using the regulator shows a 10% difference?

Thanks for the recommendations on controllers. I think I've decided that I'm going to find a little money to borrow from a friend to get a controller. I should be able to get one that measures c02 enrichment and temperatures (and kicks c02\fans on and off accordingly) for about three bills right? A friend of mine paid a thousand for a complete atmosphere controller. Any recommendations on c02 controllers??

"There are good ways to go about using co2----one of the worst ways is blowing it out your exhaust."

I feel you. Perhaps if I did invest in an a\c unit the exhaust could be kept off the entire time during lights on. The way I was going to do it was to kick the fans back on when my temps got too high. Does sort of seem like a waste but I'm trying to do this cheap for now, and then invest more money a few months from now. I have a budget of $500, but a controller\tank\regulator is going to cost closer to a grand I'm guessing. The air conditioner can come after this next run. Thanks for the info guys I really appreciate it.

Friend said he would lend me five bills for the next two months!

Thinking I will probably buy Sentinel CHHC-1 Cooling Heating Humidity and CO2 Controller

I agree about it almost not being worth it to pump c02 in your room if you can't take accurate readings about what's in the air.

max~ you don't need to exhaust air at all with your lights on?

do you run an a\c unit? i'm confused how so many of you don't need exhaust at all in your rooms in lights on period, do you all use stand alone a\c units?

McGruppsMonsters said:

max~ you don't need to exhaust air at all with your lights on?

do you run an a\c unit? i'm confused how so many of you don't need exhaust at all in your rooms in lights on period, do you all use stand alone a\c units?

Click to expand...

I use a window ac unit with NO fresh air exchange and do not vent during lights on. I had to open the window unit up in order to seal some holes to the outside part of the unit. Runs very efficient. Most portable ac units will need an exhaust in order to cool the condenser. Not ideal since they utilize conditioned space air to accomplish this, and there goes the co2 again.

Ok---What I was trying to find out was if your lights were air cooled and if you were pulling the air to cool them from inside the room or outside? Standard size exhaust fans should at least be exchanging the inside room air every 5 mins min(more is better). Yes you will get heat from the radiant light even when your hoods are cooled properly. 83 to 85 deg is a great temp when you are using co2 because the plant stoma will be wide open. A couple of things to take into consideration is that you will have to water more often than if you were not using the co2 and your humidity will go up. The 10% that I spoke of is what you should expect in weight gain over not using co2(perfect conditions will net you 20%) Perfect conditions are a lot harder to control then many make think--there are so many factors that have to be at 100%-I'm not saying you can't do it but again a realistic expectation is a 10% gain(just my personal opinion). Of all the ways I have seen the following is the best use of co2----The room is sealed air tight--the hoods(cool-tubes) are cooled from out of the room duct-the lights exhaust exit outside the room---ppms's of co2 match nute ppm---1200-1700. Exhaust of the room is tied to a timer that is set to run only when lights and co2 are off. Co2 controller is on a timer that starts one half hour after lights on and cuts off one half hour before light off.(during the on time controller maintains co2 at set ppm.) The room had 2 oscillating fans and a scrubber so there was ample air flow in the room--The ballasts were outside the room so they wouldn't add heat the the room-the room was ran during the winter and the lights on period were at night---there was no need for A/C and the room stayed between 83 and 85 during the lights on and 73 to 75 during lights off. It was the most efficient use of power and co2 because the room didn't use A/C and wasn't wasting and exhausting co2. As far as using A/C---the heat has to go somewhere so most built a room in a room with the window A/C mounted in the wall and the heat is dumped into the outside room. The portable units are the same except they have exhaust tubes that are mounted in the walls and the heat is ducted to the outside room(along with the smelly inside room air). I would be surprised if you could get 5 days off a 20 pound tank if your exhaust in that size room is kicking on all the time and if you did you would still need 12 tanks a cycle for short flowering strains--that a lot of tanks to be lugging around but then again its up to you and your needs and the situation your in. I would like to hear more in detail about unit's mods to his A/C---I would like to know where his heat is going? I hope some of this helps you out.

unity said:

I use a window ac unit with NO fresh air exchange and do not vent during lights on. I had to open the window unit up in order to seal some holes to the outside part of the unit. Runs very efficient. Most portable ac units will need an exhaust in order to cool the condenser. Not ideal since they utilize conditioned space air to accomplish this, and there goes the co2 again.

Click to expand...

Very interesting---can you post some pics and go into more detail about your window A/C and the mods you made?

DR. VonDankenstine said:

Very interesting---can you post some pics and go into more detail about your window A/C and the mods you made?

Click to expand...

Hi Doc, my grow space is in the garage and the window unit dumps the hot air into the garage. But NO air exchange takes place from inside to outside my grow space. The only .5" hole I have in my AC is to allow for the condensate to drain from the evaporator coil to the condenser portion of the drain pan where the condenser fan blows it off. The reason I had to open it up was to seal some over sized holes that the manufacturer had provided for the refrigeration line (condenser to Evaporator) It added up to like a 3sq" hole and every time the condenser fan came on my co2 along with the grow space air would be sucked out. One of the reasons to have at least a co2 counter, I would have never caught this without one.
Btw, my Kenmore unit was $240 at sears.
One can also mount the entire unit inside a larger grow room (as long as the btu's match) and just duct the condenser portion to the outside. Again, no loss of co2!

My ac unit is not exposed, it has a peg board structure around it. Not that it matters, I'm legal

How many BTU's is that unit?

DR. VonDankenstine said:

How many BTU's is that unit?

Click to expand...

It's 6000 btu

Here is a link:

Kenmore 6,000 BTU Single Room Air Conditioner - Model 75062 at Sears.com