The sparkling water is not strong enoughUpdated 6 days ago

If you follow these steps, you should be able to enjoy highly carbonated water:

1. Don't put too much water in the bottle; maximum to where the curve of the bottle shoulder begins, preferably a little less.
   
2. Press the button long enough: Press the carboniser button until you hear the pressure relief. This takes 3-10 seconds, depending on how hard you press the button; the harder you press, the more CO2 flows, and the pressure relief activates sooner. You can recognize the pressure relief by a slight "hissing" sound coming from the lid.
3. Shake the bottle: Shake the bottle vigorously after hearing the hissing sound (like a cocktail shaker).
4. Repeat the process: Press the carboniser button again until the pressure relief activates, then shake the bottle vigorously again.