C02 help PLEASE!!!

I’m running a hydro farm c02 controller.. trying to dial it in and could use some help. Do I need to set the flow meter on the regulator on a certain setting?? Also, it gives a +\- range. What’s a good setting for it? I have mine at 150 so it’ll allow the room to drop or raise 150 from initial setting. I seem to be going through a 20lb tank per week and wondering if I can switch a few things to get it to last a little longer? Or is 20lb c02 for a 12x12 normally about a week run time in veg? My room without c02 is around 400/450 if you need that. Thanks. Also, can I get away with using a crush washer twice? My shop won’t have more till Monday..

I’m not sure about any of the settings, but I do know that you shouldn’t be running co2 in veg. Am I reading that right? Other than that, make sure you have sealed everything and double seal it, then check again. Great Stuff foam works great, Gorilla Tape, and foil tape will also do the trick to get some of those final seams. Door sealed well? Sorry I can’t help more with the controller.

what kind ofair exchange rate you got?,,how intense is the lighting,,,,honestly co2 is a waste most of the time on the small scale

in the 1980's, grow books recommended augmenting CO2 up to about 389 ppm.

If you have good ventilation you don't really need extra CO2.