At $2 or $3 per bottle, you could afford to have several bottles stashed throughout your gear. Sure, it burns like fire when you disinfect a cut or scratch, but this miracle fluid can disinfect both wounds and water. Drip 5 to 10 drops of tincture of iodine (2%) in one quart of water. Shake well. Turn the bottle upside down and unscrew the lid slightly to flush the threads. Wipe down the bottle with the water that leaked, and allow the bottle to sit in the shade for 1 hour before drinking. Use 5 drops tincture of iodine for clear warm water, and up to 10 drops for cold or cloudy water.