I use an Exhale bag in a 3'x3'x6' growlab. I have never tested my ppm and I have no way of knowing if it is better. I will say that they are getting more popular. Here in Wa. State I have seen the price go from $26-$40 in the last 8months. I also have heard from the grow stores here they last a lot longer than 6months. I saw one at a store that was still producing co2 and was over a year old. So hold onto it. it may last 12 months. I have had mine for 6 months. I have only been growing for 8 months, so I am so new I probaly couldnt tell just by looking at the plant. I will say this, my shit is good and big. My 1st harvest produced 5ozs and I was using a 400hps, she was a Jack's Cleaner. I grow one plant at a time under each light. Right now I am flowering a Strawberry Cough and she is at the end of her 5th week of Flower. She is flowering under a 600hps. Plus she spends the most time with the Bag and she is in a growtent. One thing I have is that I have to water every other day. I have to have a lot of air flow so as not to develop PM. Day 38 no PM, but I did use to much calcium. My other room is a 400w hps/halide. I just started flowering the Afghan in there 6 days ago and white pistills are present. This room doesnt see the Bag quite as much. I think I will go down and buy a new one so I have one for each room. I feel the need to have one because my grow is deep in the back of my garage, 30'.
6-5-12.
My Orange Crush. I raised this from a seed on Jan. 25. Planted outside April 23. Week 19 of Vegg. There is another one, a Jack Herrer, but she isnt doin as well. Too much nitro in the soil. Still she is 3' tall. Oh, I live where I-5 and I-405 meet. So co2 for thes guys are not a problem. Plus, since I vegged them for so long, the week long cloudy or rainy weather has not bothered this one at all.
Ther that is why i have an Exhale bag, because I need co2 in my garage. i cant be running my truck in the garage, beside isnt exhaust c2o