Today is groundhog day, and it is said if the aforementioned critter sees his shadow we will have six more weeks of winter. However, if you look in your bathtub today and see a shadow, it's an entirely different situation -- most likely a little home-grown science experiment known as mildew. Once it's there, it's tough to remove. No matter how hard or how much you scrub, the dark shadow of mildew discoloration lingers on. The formula for fighting mildew is simple, but effective. Just add 1 quart of liquid laundry bleach to 3 quarts of warm water. Then add 1-third cup of powdered laundry detergent, and mix well. Scrub this solution on the fungus-darkened area, keeping it wet until the black mildew turns white. When it clears up, the mildew fungus is dead. As always, wear rubber gloves, protect your eyes, have plenty of ventilation. And that's the On The House tip for today.