CO2 and it's use question

Discussion in 'Growing Marijuana Indoors' started by Slypknow, Apr 7, 2006.

  1. I've done quite a bit of research on CO2 and 'cheap' homemade recipes. I'm considering the fermintation method vs. buying a tank. But here's what I'm not quite sure about:

    Apparently, the babies only use the CO2 when the grow light is on however one should not run a fan while distributing CO2. I'm not as concerned about the amount I need of CO2 more on its delivery.

    How do you guys normally handle it? Turn off the fans, leave the light and hit the box with CO2... then how long do you wait until you turn the fans back on? I'm sure it depends on the amount of CO2 and # of plants consuming it - but a ballpark figure on how long would help quite a bit.

    Here's an easy example:

    1 plant - 40 cubic feet to cover - kill fans - dump in CO2 - wait XXX amount of time prior to turning back on fans.

    Thanks for any insight you all can give!

  2. It more depends on how quickly your area heats up from the lights while the fans are off. You can get a CO2 controller that only runs your CO2 when the lights are on and automatically shuts it off and turns on your fans at a temperature you set.

    For instance, say you want to maintain a temp of 85 degrees. You set the controller for 85 and then plug your CO2 solenoid into the controller's outlet. The controller has a photocell on it that lets CO2 flow when the lights are on and shuts down the flow when it's dark.

    The CO2 and lights will be on until your grow area reaches 86 degrees (because you set it for 85 let's say). When this happens, it shuts off the CO2 and turns on your fans until it gets down to like 77 degrees or so and then turns off the fans and starts your CO2 back up until it gets to 86 again. And over and over and over...

    this way you're not wasting CO2 in the dark and you're not wasting it by ventilating it out of your grow room.

    The "AIR3" from CAP is a great one! It lets you set the max temp, max humidity, and controls your CO2 and exhaust. Basically, it works just like I said above but it will also turn off your CO2 and turn on your ventilation when EITHER your temp or humidity exceeds the maximum that you set.

    If you can't find one for less than $180, throw me a PM and I'll point you in the right direction.
  3. Thanks up4!

    This unit looks awesome and kinda takes the guess work outta it. I think my main issue is just how fast my box's temp climbs without a fan on (haha). I tried an xp and turned off the fan but left the light one (400w HPS). The temp soared to 95 degrees in about 5 minutes.

    I just wanted to make sure that if I dumped CO2 in there without the fans on, that it would actually be utilized in time by the plant before the fans came on and blew all of it away. If plants use CO2 that fast then cool no worries.
  4. they'll use it whenever it's available. Even when normal air is going through, you get about 400ppm. The idea is to vent your light w/ a fan and keep it sealed from the box/room. By removing the heat from the lamp more efficiently, the room takes longer to heat up. Even at 5 minutes, you'll vent all that air in a minute or two and then get another 5 minutes of CO2. It cycles on and off so you're plants do get a lot of exposure to it.

    This wouldn't really work with a PPM activated CO2 system though because of the short cycle. But with that controller I showed you on Ebay, it would be fine.

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