Hey Zandor,

The room is split in 2, one side Flower (using for Veg now till I get the perpetual thing going) the other side is draped off with plastic/velcro on sides to keep it separate (the real veg side) 2 seperate sides, 2 seperate air flows, just one divided room.

No what I have is home built controller that I just finished (and promissed to get the schematics out to the rest of the members... with kids, wife, job, and bullshit gets tough)

The controller will not allow CO2 to run if the fan kicks on with the lights on or when the lights shut off when I go to flower. Very well designed controller I have to admit, took some trial and error to get it designed right.

Anyways, The controller is keeping the CO2 at 1500 average, 24/7 in veg. Fan to move the air around the room, thermostat set at 83 (mechanical style so it's a guess) which hasn't kicked on yet so the 400 MH hasn't warmed up the room enough yet.
I haven't purged the room on it's own. Will be in veg for about another 2-3 weeks, want the tomato plants nice and full before putting them in flower.

But every 6 minutes the CO2 kicks on for about 20 seconds and raises the ppm to 1600 or so, then slowly drops to 1400 over 6 minutes before the cycle starts over. The room is about as air tight as I can get it, but could do more to seal it, I do have a slight draft (ever so slightly) entering in from the intake fan at the bottom of the room.

So, does that sound about right?
HydroDynamics Reviewed by HydroDynamics on . CO2 /Temps/Humidity Question!!! Small Grow Room Split Veg/Flower (currently vegging in Flower side to start perpetual grow). BTW, CO2 is the bomb... clones have taken off and doubled in size in 4 days, and just keep growing!!! Situation: I'm running co2 off a Telair 8001 in veg side that is demanding a boost every 6 minutes, drawdown is about 1-1.5 ppm / second between 1600 to 1400 ppm. So I end up getting a demand off the Telair for CO2 to bring it back up. Seems dialed in. BUT temps are staying at about 78-79 with Rating: 5