CO2

[fatsax]

so what the simplest and cheapest way to provide co2 for a growroom?i expect the air around here is 500 to 600 ppm since i am right on a busy main road near a town centre in a city...last time i tested a different grow room in flower i still got a decent 400 ppm and all that was exhausting i ntheir was a decent sized air pump getting rid of air into the attic and it was only a small room packed full of blueberry....
what about this sugar/yeast/water idea?
what about burning candles in the room?(when im in obviously)
i will buy a co2 generator eventually but for now i just want cheap and cheerful

fatsax Reviewed by fatsax on 07-20-2007. CO2 so what the simplest and cheapest way to provide co2 for a growroom?i expect the air around here is 500 to 600 ppm since i am right on a busy main road near a town centre in a city...last time i tested a different grow room in flower i still got a decent 400 ppm and all that was exhausting i ntheir was a decent sized air pump getting rid of air into the attic and it was only a small room packed full of blueberry.... what about this sugar/yeast/water idea? what about burning candles in the Rating: 5

[foxysox]

$250 will set you up with a tank and regulator, and a simple timer to control release.
It's the safest and most efficient way to go about adding CO2. My feeling on CO2 is this:
Get your other variables squared away before even considering it.
When it is time to supplement CO2, don't bother doing it half-assed. The yeast method works tolerably well but stinks to high heavens. Candles are not practical at all- dangerous and seriously the amount of carbon in the paraffin isn't really all that awesome, I mean, it is super lots of carbon by % of mass, but not much mass, you know? plus you are adding heat.

[Divestoned]

water,sugar,yeast. mix the sugar in the water,pour in the yeast.

Dive:stoned

[fatsax]

anyone in uk hire out co2 bottles,,,how much it costing you?

[khronik]

If you have a hot water heater that runs on natural gas, you can vent the exhaust to your grow room. If you can deal with the heat, a really safe (ie, newer) kerosene space heater or a propane/natural gas ventless heater would work well too. The main difference between a heater and a co2 generator is that the co2 generator shuts off if the CO2 gets too high (I think), whereas a ventless heater shuts off if the oxygen gets too low.

Yeast is good too, build yourself a still and turn the resulting liquid into booze. Then you'll be producing two psychoactive substances for the price of one! By the way, wine yeast or distiller's yeast works a lot better than bread yeast. It smells less too, and it'll generate alcohol at a much higher concentration.

[Opie Yutts]

The simplest way is with a co2 generator and a cyclestat timer. The best way is a PPM shut off, but that's at least $450.

[Tomthehippie]

Thereâ??s loads and loads of old threads on this! run a search in the indoor section youâ??ll find loads of threads.

[TestPilot]

As foxysox said, you can run bottled CO2 injection for under $250.

If someone were looking for CO2 and didn't want to go near a hydro store I would take a look at some aquarium stores . CO2 injection is used in living plant aquariums with a few different/extra parts.

For your room you will need:
- CO2 bottle (20lb is usually enough)
- CO2 regulator
- CO2 solenoid (120V)
- Flowmeter (Ideally calibrated for SCFH CO2, but most likely air)
- 1/8" MPT to 1/8" MPT hex nipple (1" should be sufficient)
- 1/8" MPT to 1/4" Barb fitting
- Silicone or CO2 tubing (1/4")
- Timer or controller

BOTTLE
You can usually buy or rent a bottle at a gas supply.

REGULATOR, SOLENOID and FLOWMETER
Any regulator with standard threads and an output within the working pressures of your solenoid and flowmeter will work.

You will find several brands of CO2 solenoids if you search for aquarium CO2 injection. Any should work.

Flowmeters may be tough to find. Ideally you want yours in "SCFH CO2" but you may only find them in SCFH Air. Not a problem as long as the meters materials can be used with CO2 gas. Use this conversion if you have one for air:

Q2 = Q1 * sqrt(1/1.5189)

Q1 = Observed flowmeter reading
Q2 = Actual flow corrected for specific gravity
1 = Specific gravity of air
1.5189 = Specific gravity of CO2

More specific information on the math in my other post: http://boards.cannabis.com/indoor-growing/121494-diy-co2.html#post1501420"]http://boards.cannabis.com/indoor-gr...ml#post1501420

Milwaukee makes a nice dual gauge regulator combo that includes a 120V solenoid, needle valve and bubble counter. You can unscrew both the bubble counter and needle valve and set them aside. You won't need them.

TIMER/CONTROLLER
You can get an excellent digital intermatic timer (7 day, no astro auto-adjust) for around $30. You just want a timer that can do 15 minutes or less on time, every 2 hours at least 6 times. (Only needed during light cycle of flowering)

The CAP units are GE Telaire sensors. If you're familiar with PIC or something similar you should have no problem setting up a test loop and tripping a relay. Shouldn't need much more explanation if you're comfortable with this.

ASSEMBLY
Regulator connects to the solenoid input, solenoid output connects to the hex nipple, hex nipple connects to the flowmeter input, barb goes into flowmeter output then tubing on the barb. Use thread tape where appropriate. FOLLOW THE INSTRUCTIONS THAT COME WITH YOUR REGULATOR

If you have an adjustable regulator, make sure your regulator output pressure is turned down/off each and every time you open the tank valve. Once the tank valve is open you can slowly adjust the reg pressure.

I'm not going to go into the math of flowmeter selection (based on room size and minimum on-time of timer), time calculations or gas conversions as I already covered these in another post: http://boards.cannabis.com/indoor-gr...ml#post1501420

[fatsax]

can any welding equipment be used as i may be able to get some regulators etc cheap?

[TestPilot]

You may be able to find a welding/cutting regulator and flowmeter combo, but the flow rate will likely be too high. You need more when using it as a shielding gas. The upside is, you may find one with a direct read scale for CO2 as well as mixed gasses.

If you do find just a reg, make sure the output ranges are within the operational limits of the solenoid and flowmeter (20-60psi is perfect). You don't really need more than 10psi on the output. You'll get more flow than you need...in fact, 10psi will max out your flow meter if you crank it up.

The combo I mentioned is around $70. Not bad considering it includes a solenoid that sells for around $30 online (and the other stuff you'll probably throw out).