When I first set up my co2 system I bought a gush glass non return valve. When I set this up I had canister, reg and solenoid, tubing, non return valve, tubing, bubble counter, tubing then atomiser. Every time I filled up the bubble counter the water would just leak out of the valve. I gave up assuming being hand made I had been unlucky and got a faulty one and got it refunded. I had an old plastic non return valve from my air pump which although not designed for co2 use worked properly so it stayed. I came home from working away and at some point something has gone wrong. The plastic non return valve has popped off both sections of tubing and now let's air and water travel both ways. I went to Lfs today and bought an aquagro glass non return valve gone to set it up and again it leaks air and water whichever way I have the valve. Am I doing something wrong or am I unluck with nr valves?