right this is going to make me look really stupid im sure of it. I have asked some firen dthis a few times and they have all responded in the same way as i had pressumed. Are nitro and air exactly the same or is there a difference. I have pressumed they are identical so don twant to look stupid filling a 3000psi nitro with air and killing my self if there different. I assume its just the american and english language difference. If im wrong please tell me so i can live to make anpother stupid mistake like filling a co2 bottle with ketchup!! (actually that sounds quite interestin!)