Baking soda and citric acid ratio is best 1:1, as for the water, the following is the detailed steps for reference
Recipe: (a bottle of) 1.5 grams of baking soda 1.5 grams of citric acid, a little sugar, fruit juice, moderate
Methods: a clean soda bottle, pour cold water into the bottle, not too full, about 70% of the volume of the bottle, add some sugar and a certain amount of fruit juice
Methods: a clean soda bottle, pour cold water into the bottle, not too full. Don't overfill it, about 70% of the bottle's volume, add some granulated sugar and a certain amount of fruit juice. Then put 1.5 grams of baking soda, and finally 1.5 grams of citric acid Immediately cork the bottle tightly with a stopper, and tie the stopper tightly with a thin rope or aluminum wire so that the soda does not wash out. Gently shake the bottle, the bottle produces a large number of bubbles, constantly rolling up and down, after about 20 minutes will be able to drink.
To be on the safe side, it is best to wrap the bottle in a cloth when making soda.