I have used a pumice stone very successfuly, & it didn't take too much elbow grease - just about 10 minutes of scrubbing. Tip: take your rings off; the pumice scratches the metal.

I also use Lime-A-Way (in a green squirt bottle) & Kroger's generic version with success.

I use The Works (for toilets) on mine. Another one that is great is "Wink", comes in a brown plastic bottle, strong stuff; don't put it in the tank because it will cause any rubber parts to dissolve!

Pumice stones does a nice job of removing hard water lines from porcelain toilets, I used to use it all the time. But now I've discovered the amazing uses of white vinegar. It's all I ever use for the bathroom at least once or twice a week. I put in about 1/2 cup onto a string toilet brush (available at professional cleaning stores) letting the excess drop into the toilet water, swish it underneath the rim and around the bowl, let it sit for a several minutes before cleaning the inside of the bowl. I also put a little into a the sink with some water, wring a cleaning rag in it to wipe the wash bowl and fixtures and rest of the toilet and floor. It's the safest and best bathroom cleaner I have ever used and it does a really good job of deodorizing the bathroom. And no need for rubber gloves if you don't want. If you already have a ring, use the pumice stone after the vinegar has been in there for a while, it will make removal a lot faster.

Turn off the water supply and flush the toilet.

Make a 'snake' with toilet paper and press it onto the water line. Spray the TP with white vinegar and allow to set for several hours(if bad) or even overnight(if horrid). Ring will be gone or easily removed with light scrubbing.

With some toilets you can dump a bucket of water into the toilet and it will flush and you don't need to turn off the water. (Sometimes it is a simple quarter turn to turn off the water and sometimes it is a bit of a bother so this little trick may or may not help.)

Yes, but it will refill unless you've turned it off. You want pure vinegar setting on that calcium build up. No water to dilute it.

Bar Keepers Friend works really well too. You can find it at most Wal-Marts and some grocery stores in the cleaning agent aisle. It's in a gold can (similar to a can of Comet). Use the same technique mentioned above with turning off the water supply and flushing. Then sprinkle the Bar Keepers Friend on the stain. You can let it sit for a few minutes if you want. Then use a green nonscratching scrubby to clean the stain off. Works great for orange iron stains too!

thanks guys! I will give some of these a try & see what will help!

Another idea that works well for me... I dump a bucket of water in there (and yeah, sometimes it's nasty mop-bucket water, but it does the trick of emptying the toilet) then use the the cheapest Dollar Store dishwasher detergent to make a paste. I rub it it around with the toilet brush and leave it there until I need to pee. That's when I remember to scrub it some more and flush. Just enough abrasive and bleaching agents in dishwasher powder to do the job. Recommended time: until you need to pee. Do not use this method while drinking beer.