It’s always a great idea to utilize reusable water bottles, and there are many choices when you’re shopping for one. Bottles with an integrated carbon filter are popular in the marketplace. The concept is simple: When you pour tap water into the bottle, the carbon filter cleans the water as you squeeze and drink. But carbon filters are excellent places for harmful bacteria to grow. So over time, as you reuse this bottle, you risk making yourself sick. It’s best to stick with traditional reusable bottles in glass or metal and to fill them with filtered water instead.