Your Co2 should never drop to 1000ppm when you have your computer set at 1500ppm. Using the Co2 computer should turn your burner on again as soon as it drops to 1450ppm then when your room gos back up to 1550ppm it will kick off the burner again. You might wanna try putting your Co2 sensor closer to your burner. My sensor is only a few feet away. I use about two 20lb tanks for 6.5 weeks of bud then my Co2 is turned off for the remainder of the bud cycle. What kind of burner are you using? Does your burner have a glow plug or a pilot light? With the sealed room you must use a burner with a glow plug.

Dont worry about sealing your room so tight. Plastic and tape is enough. For your heat problem you burner might not be big enough for the size of your room. I allways buy a bigger burner so my room fills up with Co2 faster causing less heat. Buying a bigger burner would be cheaper than buying a new A/C.

As for your humidy being high. Do you have a dehumidifer? I am really carefull with my dehumidifer. I use a 40 pint dehumidifer. If the humidity is to low it will dry out your leaves and make them yellow. I try to keep my humidy at about 70-75% when the lights are on. Right now because of the time of year I dont even have my dehumidifer plugged in.

I hope I have answered your questions. Im glad to try to help you out. Good luck.

Quote Originally Posted by Aaron385
On the topic of CO2 I think I have a good question for you tranoble. But before I pick your brain, I want to say super thanks for this info and I have been able to utilize some of your methods which have proven very valuable to me.

I am using a digital CO2 ppm meter/controller and I am trying to zero in on a final system for enrichment. I have a burner but my cooling system cant handle its operation if I am trying to keep ppms up for the entire light cycle. I can definatly hit target ppms range and I can stay there for a couple hours before the burner heats the room over the air conditioners capacity.

My room is a "sealed" room (thanks to this thread alone by the way), although calling it air tight is kind of pushing it, I have tried to plug every in and out to the room but I can watch the CO2 ppm meter after either a burn or injecting CO2 that the ppms really take a dive as soon as the source is shut off. I can watch humidity and I wish it would take as much of a dive as CO2 does but it does not.. which proves the room is like 99.something% sealed.

I guess what im asking, do you see CO2 ppms take a dive as soon as you shut off your burner? Like if I shut off the burner at a stabilized 1500ppm I can watch ppms dive to 1000ppms in about 5mins. Is this normal? I thought it was a sealing issue but I have "great stuff"'d the hell out every crack and I think its very tight. I would hate to think how fast I would use up CO2 cylinders.. but anyways..

It brings to question, I have read many books which preach the 4 time saturatuon per light cycle method and I havent run into any reputable info that supports a constantly increased ppm steady through the whole light cycle and you are the only one I know that reccomends it. Now, it makes complete sense, and moreover I really respect your insights. Im stuck right now with making a decision to upgrade cooling (buying an even larger AC unit) just to run constant increased ppms or going old school with 4 times a light cycle and I would really apreciate your input.

Your words are like gold to me so I would really appreciate your opinion on this!