Tough stains in your bathtub got you down? Whether they be stains from everyday use, or from drain cleaner or bleach, read below to find some good tips for winning the war against unsightly stains. This is a work in progress - add your wisdom if something works or does not work for you, or if you have any additional tips to share!
Figure Out What Type of Tub You Have
Know what it is made of. This is critical as some cleaning methods cause definite damage (or worse stains!) to certain kinds of tubs.
The most common types of bathtubs/showers are porcelain, enamel, and acrylic.
Porcelain is stone-like and the most durable of bathtub/sink materials.
Enamel is common in older tubs and is very sensitive to drain cleaner and bleach (brown rust-like stains instantly appear when the tub is exposed to bleach or a strong acid - yuck!).
Acrylic is a bit more like plastic - knock on the tub and see if it has a bit of a plastic sound to it; acrylic shower walls may bend in some places. If you have an acrylic tub, stay away from abrasives - absolutely no pumice stones; I'm not sure if scouring powders like comet are compatible with acrylic tubs/showers, so use them with care.
Use an abrasive powder, like Comet or Ajax, a scouring pad (the green scrubbing side of a new dish sponge works well), and elbow grease will work wonders.
For the grime that builds up underfoot particularly in the foot-grip areas of a porcelain tub, this method works very well.
Pour some comet on the stain allowing, add a little bit of water (but no so much that the comet dissolves and loses its grit!), and scrub away.
This is an excellent routine cleaning task to do while you are taking a shower - just bring the comet and the sponge in with you!
For tougher stains, some recommend use of a pumice stone to scrub them out (note that pumice stones are probably a bad idea to use on acrylic tubs, or refinished enamel bathtubs - a pumice stone will mar the surface with scratches).
Alternatively, just allowing a comet/water paste to set on the bottom of a porcelain tub or sink for 15-30 min, followed by a little scrubbing, can also produce an unbelievably bright white shine.
Oven cleaner has also been recommended as a stain removing solution for porcelain tubs - just be careful not to get any on your shower curtain as it can ruin fabric or plastic; also oven cleaner can cause fading in colored porcelain tubs, so it is not recommended for them!
Remember that bleach is your enemy; so are drain cleaners.
Bleach reacts with enamel tubs almost instantly and leaves behind brown rust-like stains.
Also, mildew removers that contain bleach (2% is enough!) can produce a similar stain if allowed to pool and sit on a tub. For instance, spraying the walls of the shower with a bleach-containing mildew remover and not rinsing the whole area promptly can leave rust-like rings in places where the mildew remover has collected (like under your shampoo bottles!). It can be a big shock to see those brown stains appear if you are used to dealing with a porcelain tub!
You'll want to buy a mold/mildew remover that does not contain bleach if you have an enamel tub. If it's too late and the stains are already there, don't fret - while they won't come out with standard scrubbing, there are easy ways to get rid of the stains.
Drain cleaners can also cause havoc on enamel tubs (the strong acid in drain cleaners similarly reacts with the enamel leaving behind brown stains). These stains, and the ones resulting from bleach, typically cannot be removed with scrubbing but fortunately there is an easy fix.
Hydrogen peroxide (the kind that can be bought in a drug store for disinfecting cuts; such a bottle contains 3% hydrogen peroxide in the US) can work wonders for removing drain cleaner "stains".
You can avoid the whole affair in the first place by carefully pouring the drain cleaner into the drain (drain cleaner is also not so good for the chrome/metal ring around your drain...).
Just pour some hydrogen peroxide on the stain and watch it disappear; or if you want to take the more careful approach, pour some hydrogen peroxide into a bowl and apply it precisely onto the brown stains using a paint brush. Bleach stains also can be removed by hydrogen peroxide, but they tend to be a little more persistent and do not always disappear instantly with treatment.
Rust/lime removers (like CLR, or lime-away) do not usually touch bleach stains. Some tips for getting out bleach stains if hydrogen peroxide only partially removes the stain:
Try instead a 2 parts baking soda to one part hydrogen peroxide slurry; mix it well to produce a paste, apply the paste to the stain, and let it sit for 30-60 minutes;
Also a "magic eraser" sponge tends to weaken the stain, making it easier to remove with hydrogen peroxide; just scrub the stain with the damp sponge repeatedly - even if you don't see very promising results after only using the magic eraser sponge, you will see that the hydrogen peroxide works better after scrubbing with the sponge
For everyday stains (not bleach or drain cleaner related), make your enamel tub sparkle by applying a similar 2:1 baking soda:hydrogen peroxide paste to your entire tub and allowing it to sit for 30 minutes before scrubbing and rinsing it away.
Also, prior treatment with a spray-on soap scum remover might be helpful. This step dissolves the soap scum on your tub that may be trapping dirt and grime. Removing the soap scum first can allow the hydrogen peroxide/baking soda better access to the real grime.
Use soft cleaners are the key here, since acrylic is easily scratched. Try bathroom cleaning products like Soft Scrub to get out stains in your acrylic tub or shower.
Avoid pumice stones and scouring pads!
An alternative to hydrogen peroxide/baking soda, is cream of tartar/hydrogen peroxide. This mixture reportedly also works wonders on stained tubs (though not sure what kind of tub this works on - porcelain? enamel? acrylic?) - just put some cream of tartar in a bowl and drip in hydrogen peroxide until you have a thick paste. Apply the paste to the stained area and let dry; rinse away the dried paste and watch the stain disappear.
Test new stain removal procedures on small, inconspicuous areas of your tub to make sure that the finish will not be removed or scratching will not occur.
Be careful with harsh cleaning solutions like oven cleaner, drain cleaner, CLR or lime-away - protect your eyes with goggles and your skin with rubber gloves! Use oven cleaner only in a well-ventilated area.