The beauty of the reusable water bottle is that it’s just that – reusable. You can repeatedly head to the water cooler or faucet to fill ‘er up, but when your bottle continually stays wet, you know what that means? Yep, bacteria loves a moist, dark environment. Along with your dinner dishes at night, it’s good to get in the habit of cleaning your bottle every night, or at least every three days. Here are some ways you can get rid of the germies and grime. Throw it in the dishwasher: Some bottles are dishwasher-safe, so check the bottom of your bottle or the brand’s website to make sure. Kleen Kanteen Classic and Wide Mouth stainless steel bottles are dishwasher safe, as well as some products from Nalgene , although it’s recommended to clean SIGG water bottles by hand. Wash it with warm soapy water: Pour out any leftover liquid, add a few drops of dish-washing soap and some warm water, screw on the top and shake for a minute or so. It’s smart to invest in a bottle brush so you can scrub deep inside your bottle, especially if it has a narrow mouth. Thoroughly clean the cap and straw as well

and allow to dry overnight. Use a weak bleach solution: If you’re really worried about germs, nothing stands a chance against a little bleach. It’s perfectly safe to drink from a bottle that’s been cleaned with a weak bleach solution . Just empty the contents of your bottle and fill it with room temperature water. Add about a teaspoon of Clorox bleach (other brands may not be safe for food containers), screw on the top, and allow to sit for about an hour or leave overnight if you’re trying to get rid of stains. Then rinse the bottle with clean water and allow it to dry out completely. Give it another rinse and you’re good to go. Use water bottle cleansing tablets: Many companies make this type of product, including SIGG ($8 for 20) and Camelbak ($12 for eight), or you can also get away with using effervescent denture cleaning tablets such as Efferdent. Just fill your bottle with water, drop the tablet in, and allow to dissolve and sit for 15 to 30 minutes (depending on the product’s directions). Then rinse and enjoy your clean bottle. Source

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Don’t Drink Bacteria: How to Disinfect Your Reusable Bottle