by box came loaded with co2 capability. it is electronically regulated from a 20lb tank. I believe that is supposed to last a month, but I can't remember. I also believe the idea is to elevate the localized concentration to (I believe) in the order of 1200ppm. Along with this goes up the need of proportionate increases in light water and nutes. I have also heard that it helps to have warmer temps when the CO2 goes up. I believe I had good success with max. temps a little over 80F. You are essentially turbocharging the air the plant is breathing and it needs more "stuff" to feed its voracious appetite. How do you know how much more? I am less interested in any specific changes to schedule and related quantities, and more interested in watching the plants and their response to the care I am giving. Up water/nutes a bit and see, then adjust maybe some more. I think there should be a way to modulate the delivery of the CO2 from your mom's O2 system. But that is beyond my technical capacity...my machine gives a squirt, I think it its every 15 minutes or 30 minutes. can't remember. Good luck. I'll keep watching. I think I've said it, but, I love that room. ;o) Walk On!~