just done my first nitrous hit .

You don't want to breath the nitrrous used on engines. It has a small amount of sulpher dioxide in it. It will make you sick as a dog.
PS: I fill my own 10lb bottles from a sixty some lb mother bottle. I have a freezer in my shop, and keep my bottles about -20 f. Then I put the mother bottle out in the sun, and use the pressure diff to transfer imto the 10 lb bottles. Have to be carefull you don't over fill. The bottles need "headspace" or they can explode, or rupture the safety disc, if they get too warm.