I am a hobbyist and been working on getting better at TIG welding aluminum.

With that, I bought a full tank of Argon a couple of weeks back and set the flow to about 15 cfm and it read 2000 psi full. It reads 1000 psi now.

The arc sputters and jumps even at high frequency AC like it is contaminated. Could I be out of Argon even though it reads 1000 psi?

Thanks in advance for any feedback.