On mine, I have a hinge that is a slide hinge, which the end tightens for harder hinging and loosens for looser hinging. I think it's a prop slide hinge. It is on one side and when the tank goes up, it sticks, and you can tighten or loosen it and then when you're done you just let it go or slide it down harder. It works wonders for that type of setup, as that is what I have on my Tru Vue 75. The top hood lifts up like a trap-door.
Renee