Hi, I just got myself a scuba tank, but it seems different from the other ones i've seen. Where the "hole" is to fit the fill station, it is metal with like a little allenkey hole in it. Am I supposed to unscrew this?
iv got a 10 ltr 232bar(3000psi) bottle and i get 2-3 full fills of 3000psi then start 2 get a drop off in fill but not majorly until about my 5th-6th fill