>>939449621
Helium suppliers ALWAYS mix other gasses in for safety and to reduce cost, even if it says 99%. You need 99% helium, and even those suppliers of 99% most often fake the percentage. If the percentage is off you WILL feel like you are suffocating to death.
Just go get nitrogen dude.
And you need tubing, if any oxygen gets into the bag before you put it on your head it will feel like you are suffocating to death. There has to be no other gasses present. Even oxygen.