Instead of using chemicals to clean your bathtub, use vinegar and baking soda. Spray vinegar heavily on tub then put baking soda on cleaning rag and rub over vinegar, the smell isn't too great, but keeps all the harmful chemicals from damaging your finishes, not to mention the environment.
This will also help keep your drains clean and smelling good.
I use apple cider vinegar when doing my shower and tub. I also use the baking soda to wipe it down. You can soak your shower head in vinegar to remove lime scale and build up as well... it leaves them sparkle.
This is an awesome tip especially if you have well water and dont want to contaminate it with chemical runoff from commercial cleaners. It's a great idea for the Earth no matter what. Thanks!
Careful with fiberglass tubs. Baking soda will take the finish off after a period of time.