I tried EVERYTHING to get the bottom of my tub cleaned. Calcium and lime removers worked for the sides but not the bottom. I tried letting bleach sit overnight in a couple inches of water, I scrubbing with comet, and tried all kinds of sprays. Finally, after reading all the things that baking soda does, I put some baking soda in, mixed with a little vinegar and scrubbed. IT'S CLEAN! - Submitted by Amy
Reminder: Be careful to never mix household cleaners, especially bleach with a product containing ammonia. Baking soda and vinegar are fine to mix.