Well that's good to know,I know nothing about whatever carpentry skills you may have so I couldn't help asking.Could you move back and take a full photo of the rack?It is an air line tube however that is not the main point of the picture. If you look at the wood and the metal you will see the metal is going inward.
I did not build the rack myself, if I did it would have been stronger than this crap.
Hello; This.get the tanks off of it, at least off of the shelf that's warping. Especially if you sleep next to it. Maybe you can add some kind of brace to the bending shelf to firm it up?