Make sure your water is safe to drink. Tainted water can make you sick. Here are a few ways to purify should be need arise. Learn a few different methods. You know, as a back up. Just in case.
filter first, purify second
If you notice debris or if water is cloudy, use a filter before before purifying. Inexpensive coffee filters are a good choice, as multiple layers of cheesecloth, or even clean t-shirt fabric.
This is the healthiest. Once water is boiling it is more than ready. Pasteurization occurs at 149 degrees Fahrenheit and to get water to boil it has to reach 212 degrees so if it is boiling it is ready. Keep in mind that boiling water will use up other valuable resources (time, energy, fuel).
my fav is the WAPI (water purification indicator). The small plastic tube is dangled into a pot of water, the green wax melts when the water temperature reaches 149 degrees. When this occurs, the water has been pasteurized. The WAPI cost less than $10 and can be purchased at http://www.sunoven.com
Is another alternative. Do not use bleach that has additives (scents, phosphates, or soaps). Also keep in mind that bleach loses its effectiveness over time, so keep an eye for expiration dates. Shelf life of 16 months loses about half effectiveness after only 6 months. write the expiration date on outside in a place you will see it.
Add eight drops, or 1/8 tsp per gallon if it is clear. otherwise follow the chart below. Once the bleach has been added, stir it thoroughly and allow it to sit for 30min.
portable water filtration device good for purifying small amounts of water. Great to have in go bags and/or around the house.
other ways are calcium hypochlorite, uv light, water purification tablets
For the record: dusted off my WAPI and stored in a place I hope to not forget where it is. Purchased bleach. And chose the filter I want to get for the house.