4. Add water to concentrated liquid or powdered formula

Formula comes in three forms:

Do not add water to ready-to-feed formula. But you need to add water to concentrated liquid and powdered formulas. Follow the instructions on the product label.

Water safety

You can use clean tap water or bottled water for concentrated liquid or powdered formula.

If you use well water, have the water tested for chemicals, germs, or minerals that may be harmful. Your local health department may provide a testing service.

If you worry about your tap water or your baby has a weakened immune system, boil the water for one minute. You may need to add more time based on your elevation. For every 1,000 feet (305 meters) above sea level, add one minute to the boiling time. After boiling, measure the amount of water you need for the bottle and let the water cool to room temperature. But use the water within 30 minutes of boiling or throw it out.

Fluoride

Tap water may have the chemical fluoride added to prevent tooth decay. Fluoride also may be found naturally in well water. Drinking water with high levels of fluoride over a long time can raise the risk of faint white lines or streaks on the teeth, called fluorosis.

If your baby drinks only concentrated liquid or powdered formula, you can use low-fluoride bottled water some or all the time to make the baby's bottle. Labels on this type of bottled water will say:

If your baby uses only ready-to-feed formula or you only use low-fluoride bottled water for formula, talk to your healthcare professional. Fluoride-containing bottled water or fluoride supplements may be suggested.