If fluoride concentration of community water is___________ppm, no need of any flouride supplement at any stage.
Supplemental fluoride depends on the age of child and F- level in water.
Below 4 years, fluoridated dentifrices are not recommended
Below 2 years, F- tablets are not recommended.
Below 6 years, F- mouthwash is not recommended.
If F- concentration of community water is >0.7 ppm, no need of any F- supplement at any age.

Essentials of preventive and community dentistry 
Soben Peter 
5th edition
>1 ppm
>0.7 ppm
>2 ppm
>1.5 ppm