My 8-year-old would spend hours in the pool if I let her, but I’m worried about all the chemicals in the water. Are they harmful?

As long as they are used appropriately, the chemicals in pool water are not hazardous. These chemicals have been used for decades. If you have a residential pool, be sure to follow the manufacturer’s instructions when using chemicals and make sure they are stored properly and securely.

Chemicals are added to pool water to kill disease-causing germs, improve water quality and prevent the growth of algae. However, chlorine is not always effective, and even with modern disinfecting and filtration systems, swimmers can still get sick.

It is important to remember these rules to help maintain water quality in your pool:

• Do not let your children swim when they have diarrhea This is especially important for children in diapers.

• Tell your children not to swallow pool water Try your best to avoid having pool water get in their mouths.

• Practice good hygiene Take a shower before swimming and have your children rinse off too. Germs on your body can end up in the water. Wash your hands -- and have your children wash theirs -- after using the toilet. Also wash your hands after you change a diaper.

• Take your children on bathroom breaks Or check diapers often. Waiting to hear "I have to go" may mean that it’s too late.

• Change diapers in a bathroom and not at the side of the pool Germs can spread to surfaces and objects in and around the pool. Wash your child thoroughly with soap and water before swimming.

Expert Thomas Felger, M.D., is a family physician from Granger, Ind., and a clinical assistant professor of family medicine at the Indiana University School of Medicine.