Building a co2 system

Allright ic, I'm gonna build a co2 tank system for the grow. All parts are ordered and should arrive within a week. Parts list includes, digital co2 monitor with built in relay (24vac), power supply (24vac output), solenoid valve with 24vac coil, large co2 tank(50#) and regulator.
All construction will be photographed and documented to share out here whether it works or not. This project is costing around $250 foe everything, not to damn bad me thought based on kits at stores are in the $500 range with no tank.

*I'm starting this now in hope that anyone with a (watch out for this) pointer will chime in so I don't hurt myself.

I hope this will give my nugs that rock hard fullness that my grows have lacked thus far. My grow area is sealed, siliconed, screwed tight with a/c, heat, lots of air moving and sealed externally ventilated reflectors . I feel as my plants get in the later stages of flower they begin to starve for co2. They flower under 1k hps on a mover and do great until the last few weeks when I think they should turn into rock hard nugs but instead keep that fluffy feel, real noticable when dryed.

All tips, tricks, bitches, moans and groans are welcomed. Help is appreciated.
Thanks,
2buds

6-28-06 Still waiting on the ppm monitor and transformer to run the monitor and solenoid valve. Think I got the monitor relay thing figured out.

6-30-06 co2 monitor is in, gonna try and set it up tonite.

Ill be watchin.. put it together for us man. Good luck.

How big is your grow area? I've heard several people complain about lack of bud density using light movers.

$250!?! hot damn thats perty affordable, when i looked for one it was gunna be like 700 with tank and i gave that the big F#%k you. but ive since taken down my 400w closet after OG went down i wont lie got a little paranoid. haha. and i just have no need for that much bud anymore in a new living space and reall dont have the time nor money to put back into a 400w+ setup ill keep it micro.

Parts are in

Parts are in

Allright, the parts are in. First thing first, everything was tested to insure the valve is valving, regulator regulates, sensor senses and trips the relay. Now to pick a spot for everything. This looks good.

Now we got a spot we'll get the regulator and valve assembled.

and do a test fit on the wall

Now that we know it fits we need to drill a few holes for the wire and tubing

The tubing runs straight into an 8" duct that blows directly into the grow area. The duct is contained inside a wooden cabinet with a furnace filter filtering the incoming air before it goes through a carbon filter. Clean air for the ladies, shit the air out here is better than in my house.

Now we take the co2 monitor


and mount it next to the intake filter, which is dirty.

All wiring is run inside the box where there is an electrical outlet to supply power.
In wiring this device I used the normally closed pair on the relay so co2 is injected till the meter reaches the set ppm then flips the relay there by cutting the power to the solenoid valve. I set it at 1200 the first nite, after power was connected it took about 1 minute to bring the area up to 1200ppm then it cut off. The solenoid valve uses the same 24vac that the monitor requires for power that way all can use the same power supply and 2 different power supplies aren't required.
Here it is working the first time:

you can see the frost on the tubing.
Here's a pick of everything installed, connected and doing its thing


After a tube of caulk and some weatherstripping I feel pretty good about things being sealed.

Also after the ting ran for one nite and I seen how much co2 was used(must not be sealed to good) I have lowered it to 800 ppm to insure that the plants aren't deprived of co2 while I continue to fill gaps and cracks.
All total with 2 trips to the hardware store for tubing and some thrifty shopping I spent around $250 including owning the co2 tank.

That was it everybody, as I read it again or think of any useful pointers I'll edit them in. Any questions just ask. I plan to install a piece of chain in the corner to make sure the tank never falls over.
Peace everybody.

beautiful!~! were both men of plywood!! rock on!@

Good find on the Telaire controller. $250 is a very good deal! I paid $500 for my CAP Fuzzy Logic, but then it is all pre-wired with an outlet built in and a light sensor. You could just put yours on a timer for lights out.

The only other problem I see with your setup is that it lacks a flow meter or a means to regulate/view flow at a very slow rate.

This will solve that: http://www.dwyer-inst.com/htdocs/flow/SeriesRMPrice.cfm#CRA

Also, I'm not so sure I understand why you need to use a intake/output fan setup when the room is sealed. Are you filtering air inside the sealed room? What is the point?

Also, did you put a volt meter on the analogue output and measure the ppm since you bought the meter without a display? hitting your setpoint in one minute tells me that you are probably overshooting. that could be another reason why it's using so much CO2.

What is the size of your grow?

Howdy Cadillac, MTF, Trev, bandan and Blind. Thanks for stopping by and checking it out.

Blind-You could just put yours on a timer for lights out.
There's always a light on somewhere.

Blind-The only other problem I see with your setup is that it lacks a flow meter or a means to regulate/view flow at a very slow rate.
I wondered about that but figured the sensor measured ppm so it would react no matter the flow???

Blind-Also, I'm not so sure I understand why you need to use a intake/output fan setup when the room is sealed. Are you filtering air inside the sealed room? What is the point?
Its cut into 4 rooms basically, the center room where the intake is at is the cooled room with ac, the air is drawn out and blown into the veg and flower rooms then passively passes back to the center room. Run it through the filters to kill the smell as better safe than sorry.

Blind-Also, did you put a volt meter on the analogue output and measure the ppm since you bought the meter without a display? hitting your setpoint in one minute tells me that you are probably overshooting. that could be another reason why it's using so much CO2.
Nope. Not using the outputs just the relay as an on/off switch. I wondered about how fast to inject the co2. I geuss slowing down the injection would allow the sensor to respond more acurately since the co2 wouldn't flood the environement so quickly. Could be?

Blind-What is the size of your grow?
Overall area is about 220sf, only about 100sf is used for growing 10'x10' total.

After changing the set point to 800ppm it seemed to cycle about once an hour for just a few seconds. The regulator is set at about 20psi. The meter consistantly read around 600ppm in the house with a few people in here so I figured around 800 would be a higher amount than ambient air but not so much the tank runs dry in a week. Also the co2 is sent straight to the plants then is measured on the passive pass back to the intake so the levels in the plant area should be a bit higher.(my thinking not proven) I am considering a flow meter so I can measure over an hour period how much co2 is vented for how many seconds, kinda measure usage but it don't matter as long as things get better.

Peace

Cut the regulator down to around 5psi, just trickles out when activated, in doing this the system took about 1.5 minutes to top off the air at 800ppm, I'm thinking this will use less co2 as I am not overshooting my target as implied by blindDate with the injection happening so suddenly. Its only been a few days but my WW plants sho do look frosty. I also managed 1 female skunk durban poison freebie plant from the free seeds and it seems a bit frostier tonite. Any co2 is better than none.
How long should a 50lb co2 cylinder last if filled completely? I think the guys jipped me on some co2 since my outofshape stoner ass was able to carry it by myself up a flight of stairs supposedly filled.
Can anybody tell me what your cylinder pressure gauge reads on a full tank?
All comments are welcomed, especially bubble bursters that may see problems I don't yet know of.
Ya'll let me know what you think or do I need to add some porn to get some comments???
Peace

2Buds,

In a room that small a 50 lb cylindar should last at least 3 weeks minimum. That is with the room completely packed with plants.

Can anybody tell me what your cylinder pressure gauge reads on a full tank?

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CO2 is a liquid, hence the tank is not filled by pressure, it is filled by weight. In your case 50 lbs, so the tank should weigh 50 lbs plus what the empty tank weighs. CO2 develops pressure as it turns to gas, so your regulator should read about 850 psi so long as there is some liquid left. Once the tank is empty (of liquid) the pressure will drop. The only way to determin how much is left is to weigh the tank. I used to keep mine on a bathroom scale so I could see how much CO2 I would use each day.

You absolutely need to put a voltmeter on the 0-10 VDC output and measure exact ppm. Something is seriously wrong. This is where buying the cheap meter without a display bites you in the ass.

Lowering your PSI means nothing because we don't have a clue as to the orifice size. That is why I said to measure FLOW. Based on what you have written, my guess is that your flowing CO2 WAY too fast.

Also, ppm should be set at 1500-1800 for results or else why have it in the first place?

I just did a quick calculation and based on the info you've given (800 cubic foot room filled to 800 ppm in 1.5 minutes assuming an ambient level of 400 ppm) determined that your flow rate is 12.8 CFH. That is 6 times faster than I would recomend, but I think it is even faster than that if you are overshooting.

Thanks BlindDate for helping me with my new toy. Help is always appreciated as are comments.

Gauge is reading around 875 for the tank.

I can wire a set of leads from those connections so's I can attach my multimeter in the grow but what am I watching for? I don't have a laptop to take offsite and plug up to the monitor so I can watch the actual co2ppm readings. Always something biting me dang it. BUT that's why I posted this in hopes that someone will learn from my mistakes as I will and have 100% success on their project.

A flowmeter is being worked on-one of my buds is looking, says he had one in the garage still in the box, hopefully a few pieces of brass and it'll be part of the setup.

The solenoid valve is an 1/8" opening reduced into some 1/4" OD ice maker water line.
I believe the orifice is a 3/32 on the valve.

Lowering the pressure was all I could come up with for slowing things down It did extend the amount of time it took to raise the levels in the room.
800ppm for now while I fill in gaps, another hour tonite with foil tape, caulk and rubber weatherstripping trying to find all my leaks. I figure some co2 is more than they had if its triggering the relay at 800 then its not hurting anything and I'm not consuming large amounts of co2 just to leak it through gaps in the wood.

Thanks again BlindDate for taking some time with me and helping dial this thing in to a working piece of hardware and I hope this helps someone else in deciding to build or buy a co2 system.
Peace

You seem to be on the right track, keep going.

Regarding the 0-10 VDC output: That voltage is directly proportional to the zero to maximum ppm capability of the meter. So for example, if the limits of that meter are 0-2000 ppm and you measure 5 volts then that will equal 1000 ppm. Get it?

I believe I do BlindDate. So what your suggesting is watch the voltage there by watching the ppm to make sure the co2 monitor is triggering the relay at my set point. If I set the limits to say 600-1600 then each increment 700,800,900,...-1600 would equal 1 volt each or 700=1,800=2,900=3,1000=4,...and so on; then I could watch and see how far above my set point I'm going and slow the injection rate down to avoid exceeding my set point by more than what a 100ppm? What flow rate would you recommend for adding co2 into an environement,1 scfh, 2scfh or just try to dial it in based on my environment? Also I believe my tank pressure fluctuates with the indoor temps meaning the colder it gets inside the lower the tank pressure. Does this sound right? BlindDate, you got any thing you recommend I should read bro about co2 in the garden? Thanks again BlindDate.
Peace

Edit: Found this link in another thread http://www.hydroponics.net/learn/co2_calculator.asp

Phew, so much info...hard to take it all in when you haven't got much experience w/ co2.

Blind date, thanks for your input...helping me make sense of it all

Instead of starting a thread about my co2 situation I'm just gonna kinda sit in on this one if you don't mind 2buds...while we got BD here I want to see what he thinks of me setup

I got a 3x4x6 sealed box, 72 sq. ft 400 watts hps, air-cooled hood, ready and waiting for a co2 system

So far from what I've read all i need is a tank, regulator, solenoid, flow meter, timer and a digital monitor like the one 2buds has

Also using the calc if I use 1 cfph, it says it should be on for a 5 minutes, assuming I get the digital monitor, I would be able to fine tune it so that I'm not wasting co2 right? Is there any guess work as to how much co2 plants consume per hour or something so I wouldn't have to get the monitor?

I'm trying to get just the bare parts now, i see my plants everyday so I don't need a fully automated system w/ monitors and all that stuff, although it would be really cool to do it right

heres a pic of the box, so full of potential!

2Buds, Read your manual, It's not proportional to what your limits are set to, but rather the zero to maximum reading the meter is capable of reaching. From what I read online that meter reads from 0-2000 ppm, therefor 0 volts = 0 ppm and 10 volts = 2000 ppm. Get it? Every 1 volt is 200 ppm.

For example; If your reading is 5.32 volts, then multiply that by 200 to get 1064 ppm

BlindDate, let me start by saying Thank You for coming back in here over and over and helping with this!
Hey Killa, sent you a PM before I looked in here and seen you posting.
Yep I got it man. I hooked it back up to the pc yesterday along with the multimeter hooked the voltage outputs and fully understand the volt reading to the ppm reading. I'm waiting on the flowmeter BD and I'm thinking about putting it on a timer so's it runs 4 hours(2nd,3rd,4th & 5th hour) out of the 12 hour cycle. I would like to get 2 months out o fthe tank.
I tell ya'll something, its fuggin amazing how much co2 you emit just by breathing. Now I know why mosquitos love me! Set the monitor up in the house for a day, when we first get home its about 400ppm, by the end of the nite with 3 people and a dog its hovering around 1200-1600ppm. I just need to push the air from the house to the grow, co2 prob solved except for the 100+ feet of pipe and the fan to push it but it may be cheaper than all the parts added together. If you grow inside your house I'd say you have your co2 prob taken care of.
Maybe some hamsters on a spin wheel chasing cheese breathing like a mofo would make enough co2.:smile:

I used to grow in a cabinet in my house, and never had a problem with bud density or quality...that might explain it

the buds I've been harvesting lately look like they've been grown under a small wattage HPS

I think a 50# tank would be able to last that long once you have it dialed in. I think the timer and flow meter will really help you out conserving the gas. I'm a little bothered by the idea of having to fill up the tank every month..but whatever

killabrown420 said:

I'm a little bothered by the idea of having to fill up the tank every month..but whatever

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Me Too Killa, Me Too.

50 lb tanks are really hard to manage without a dolly. its hard to sneak them into the house and they wont fit in the trunk of a smaller car. a 20 lb tank lasts me 3 weeks in flower with a sealed 3 x 4 x tall room. if your room is well sealed, the size of the room isnt proportional to the amount of co2 used, what I mean is a room twice as big wont use twice as much co2 cause you wont have twice the leaks.

as far as general thought on co2, Im not gonna use it next grow cause it adds more hassles than its probably worth to me, and some risk of exposure with filling the tank every 3 weeks. That said, I did grow a 3lb 10 oz tree in that 3x4x tall space, and I doubt it could be done without co2