The sparkling water is not strong enoughUpdated a month 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.

If your water does not reach the desired level of carbonation despite following the steps above, there may be an issue with the seal in the cap.
In that case, please refer to the following article:
Guide to the Cap Seal