Your water kefir grains need to acclimatize to your specific water. It may take about 3 full rounds of making the water kefir for your grains to get used to the minerals in your local water. Don’t give up. There is nothing wrong with drinking the water kefir if it is flat after the first ferment. You still get the probiotic health benefits. It won’t help the fizz factor if you leave the day 1 ferment for a day or 2 longer. The only thing that will happen if you leave it longer is that your water kefir will be less sweet. The best way to know if your fermentation is working is to taste the mixture when you make it and then taste the mixture after 24 hours. If it is less sweet, then it is working. Many people assume that something is wrong with their grains. Grains don’t go no good. They will change color based on the color of sugar that you are using. If the grains plump up after 24 hours, it is an indicator that they are being fed by the sugar and fermenting. Remember that having a warm temperature is always key for fermentation to work at it’s best.