I have a strong mildew smell coming from the shower drain. This is a 2yr old Florida home built on a slab. I have used draino, bleach, and boiling hot water. The weather is great now so I am able to leave the windows and door open in the bathroom, even with this you can still smell mildew in the drain.

Most bad oders in bathroom drains come from rotting hair mixed with grease from the soap. Try this. Tonight before you go to bed pour 1/2 gallon of bleach down the shower drain and let it set overnight. Next morning flush it down with a few large pans of boiling water. The bleach will start to dissolve and soften the hair and make it slippery and the boiling water will melt the grease and flush the mess out into the main. Now see if that smelly drain doesn't smell sweeter? Hope this helps . Tom

I think Tom nailed this one. Tom's bleach works well but I have a fun one to try if you are game. Mix 1/2 cup of table salt with 1/2 cup of baking soda and dump into the drain, then add a cup of vinegar and watch the volcano. Flush tomorrow with the bucket of very hot water. Both procedures should help you.