Quote Originally Posted by Opie Yutts
I finally have enough funds so that I can expand my set up and use co2. I have researched this and have heard varying reviews. Some say it doesn't really make that much difference, and some say it makes all the difference in the world. I thought I would see for myself.

For my flowering stage I have a space about 3' x 3' x 8' tall, and I use an enclosed hood with a lot of air pumped over a 600W bulb. This air comes from a big inline fan that has a big filter on it, which filters out the weed smell mostly, and airborn debris a little. If I don't have this fan on, temperatures reach 105F within 20 minutes.

My understanding is that plants use co2 only when the lights are on. How can I use it without it all being sucked out of the room, thereby making it useless?

The only solution I can think of is to tear apart my set up and totally redesign it so that the light has dedicated ventilation that comes from and goes to somewhere outside the room, and refrain from ventating the room at all until the temp reaches about 95F (which I imagine would take less than an hour). All my ducts are behind the wall which would really make this makeover a suckie and time consuming experience.

I have never used co2, so does anyone with experience (or not) have any other ideas? I don't see how anyone with an enclosed space can use co2 without the temps getting to hot for the plants, unless they are using flourescent lights for flowering. If that's the case they are not concerned with yeild anyway.

thanks
First off; those who say CO² does nothing have no clue what they are talking about and don't follow any of their advice.

You are correct in your line of thinking and you don't need our help. Make your change on your next round when you can make your room sealed. You want to keep it cool to around 85-88f when you use your CO². You don't want to go over 93f for long periods of time or you run the risk of Hermies from heat stress.

http://www.hydroponics.net/learn/co2_calculator.asp

That is a link to a calculator that will tell you how long to run your CO². The idea is to bring the gas level up to X point. (about 1500-1800 ppm) and hold it there for hours. The plant will use up some and that needs to be replaced. A controller is the best way to go but the cost is way to much for most people. You only exhaust the air once a cycle maybe twice but once is enough. When you run your exhaust you turn off the CO² about 2 hours before you swap out the air.

Good luck
Zandor Reviewed by Zandor on . I guess I can't use co2 in my set up. Or can I? I finally have enough funds so that I can expand my set up and use co2. I have researched this and have heard varying reviews. Some say it doesn't really make that much difference, and some say it makes all the difference in the world. I thought I would see for myself. For my flowering stage I have a space about 3' x 3' x 8' tall, and I use an enclosed hood with a lot of air pumped over a 600W bulb. This air comes from a big inline fan that has a big filter on it, which filters out the weed Rating: 5