As with any safety issue, the best response is a "layered" approach:
* Most importantly, surround the pool with a child-proof fence, which will keep children away from the pool entirely. A properly designed and installed fence cannot be climbed and should have a self-latching gate that can be locked, with a handle that is too high for small children to reach.
* A second layer of protection is to have a pool alarm. Pool alarms float in the water and make noise when they detect an object (such as a child) that has fallen into the pool.
* Pool owners should take the time to learn CPR. Even the best safety systems sometimes fail, and knowing CPR can save the lives of both young children and adult guests who fall into a pool.