Originally Posted by phreeky
Can somebody please explain what the gauges are for? I'm assuming one is the pressure of the bottle so you know when it's time for a new one, is the other the pressure that it is regulated at? Are the regulators normally adjustable, and if so do you normally also have a needle valve for bubble rate adjustment? Seems odd to have both.
One gauge shows how much is left in the bottle, and the other shows how high you have it cranked up. Since you only need a tiny amount for a fish tank, the needle valve lets you adjust the amount you are using even more to get it spot on. At least this is what I think I've figured out. Someone please correct me if I'm wrong.