When to change gas.

[roadrunner]

Hello all,

I on my 3rd keg running Boddingtons and running mixed gas.

My gas gauge is is a tad over 500 were the red begins (micromatic dual GN1773), Beer Regulator - Double Gauge - Nitrogen Regulator - Premium Series.

My question is when should I change the gas? I have a back up tank.

Thanks

[psychodad]

Change it when empty. It is going to hover over that red area for some time. Once it dips so far watch the secondary gauge.

[roadrunner]

Thanks, secondary gauge finally dipped below 32PSI.

[Scott Zuhse]

The high pressure gauge on a primary regulator will slowly drop with a gas blend cylinder as it simply holds gas. Unlike CO2 which is in liquid phase and the high pressure gauge will not drop until the liquid is gone and all you have left in the cylinder is gas. This is when you will notice that the gauge pointer beginning to fall and it is time to get nervous.