Origional post by linyoc here https://vexforum.com/t/when-i-inflatable-gas-tank-only-about-pressure-inflated-to-1-0/25812/1 reposted so people can help out
Have you read this guide? http://content.vexrobotics.com/docs/inventors-guide/VEX_PneumaticsKit-INST-083111.pdf
I suspect that you are leaving one of the output ports of the solenoid valve open and that the reservoir is simply leaking through this open port.
Please can you send photographs of your setup.
I would think that be 1.0 he means 1.0 Bars.
For those who have no idea what a Bar is, it is equivalent to 14.5 PSI.
He could have the input and output reversed.