Hi new to this and still on the learning curve, ive moved over to using a pub co2 bottle and bought a new regulator but when i conneted the bottle up the gauge was reading almost empty, so i went and exchaned it for a full one only to see a simular reading on the gauge , found out after that the first bottle was also unused as my friend had got it from his brother that runs a pub. the flow gauge seems to be working but i cant understand why the presure gauge is still only reading just over the empty mark on a full bottle. can any body explain ,, thanks