Apples, pears, carrots, celery and other fruits and vegetables, there is no need to add water, because the original juicer directly pressed the ingredients into juice. The juice is very pure and delicious. And you can squeeze mixed juices.
Of course, juices squeezed directly from fruits, such as grapes and other juices, are very sweet. If you prefer a lighter flavor, you can add water in moderation. But as far as I know, it's usually not added.
There is one exception, that is, juice for children to drink, if the child is less than a year old, then it is necessary to water, freshly squeezed juice and water ratio is 1:2 or 1:3, even if this is the case, the baby should not drink the total amount of juice per day, the best not more than 100ml.