Mold and mildew love damp spaces — and a reusable, sealed water bottle is the perfect place for it to grow. Follow these easy tips to keep your bottle safe and clean for drinking before your next workout.

Keeping your water bottles clean after each use is the best way to keep mold and mildew away. Wash your water bottle thoroughly with lukewarm water, sponge and some dish soap. If the bottle has a mouth piece, such as a bite valve or straw, be sure to give that a scrub as well. Use a cotton swab to reach tiny crevices in the mouth piece. Drain and air-dry your water bottle with the cap and mouthpiece off.

If you see spores of mold or mildew on your bottle, don’t freak out! Kill the mold by washing it out and filling with cold water, and add a few drops (no more than a half teaspoon) of bleach. Shake the bottle; squeeze through the mouth piece and let sit for a few minutes. After it’s drained, let it air-dry. Once it’s dry, give it another quick cleaning with lukewarm water and dish soap, or put it in the top rack of your dishwasher (if it’s dishwasher-safe). Keep it stored in a cool, dry place until tomorrow’s workout.

Not thrilled about using bleach? A few natural ways to get rid of mold and mildew include using white vinegar (undiluted), tea tree oil (diluted in water) or 3% hydrogen peroxide (diluted in water).

Make your life easier with cleaning supplies that are created specifically for water bottles. Camelbak sells cleaning products like brushes and cleaning tablets. OXO has a $10 cleaning set complete with a detail cleaner designed to reach the crevices in a water bottle’s mouth piece.