I run a DR240w secret jardin tent. (240cm x 120cm x 200cm).
I set up CO2 about 5 days ago. and the 5KG tank i bought is already empty.
I run at 1,000ppm, with ambient air being about 350 in my area(urban).
Its a sealed tent, only leaks i can think of are zips, a couple of tiny tears(1-2mm)...