Water & Nutrients. Like humans and animals, plants need both water and nutrients (food) to survive. Most all plants use water to carry moisture and nutrients back and forth between the roots and leaves. Water, as well as nutrients, is normally taken up through the roots from the soil.
Changing from puppy food to adult food depends on the size of your dog as an adult. If he is a small breed and will not exceed 30 pounds, he is mature at 10 to 12 months old. Some small breeds are mature before 10 months of age. Medium breeds are dogs that do not exceed 80 pounds at full growth.
At the end of the weaning process, around 8 weeks of age, pups should be fully graduated to eating solely puppy-specific solid foods. The furry babies should be eating four meals of puppy food each day, with fresh water available to them at all times. When the little ones are fully weaned, between 8 and 12 weeks old, you can adopt them out because they are no longer nursing at all or dependent on their mother for nutrition.