The moist and damp conditions in your shower can cause your shower drain to smell and a buildup of hair and soap scum form a breeding ground for bacteria. To eliminate the odor and the germs, clean your strainer regularly by soaking it in vinegar. Also, you can pour half of a small box of baking soda down the drain, followed by 2 cups of vinegar. Let the mixture travel down and bubble inside the drain for an hour. After an hour, pour a gallon of boiling water down the drain to rinse away the gunk. Keep in mind that boiling water should only be used on metal pipes. If you have PEX pipe, run hot tap water down the drain. Boiling water will damage PEX pipe.
Shower drains and PEX Pipe can be found at www.supplyhouse.com.