Since I had granite installed in my kitchen, I have been doing a lot of reading on the subject of cleaning it, and it seems that recommendations are to use products that are neither too alkaline or too acidic. But you need something acidic to remove the calcium. Vinegar is the first thing that comes to my mind.

If I were you, I would use vinegar or one of the products you had success with. Just make sure you don't leave it sit on the granite for a long time.

The only thing you can do to granite is seal it. It might help, but it seems that you would then have calcium stains on the sealer. The other thing you could do is keep a small towel handy to dry up the spots of water.

Have you thought about a water filtration system? Whole house would be ideal, but you could also just install one on that sink.

By stain do you mean something that has soaked into the granite? I have hard water deposits around mine: kind of crusty-looking. I have not wanted to use vinegar since that is not good for most stones like granite. At the same time I have a dark patina on my faucet so am afraid of using something abrasive like a powdered cleanser. I have had good luck just scraping them off using a non-serrated old paring knife or narrow putty knife, being careful to keep the blade flat against the granite to avoid nicking the faucet.

One suggestion to make the cleaning a bit easier: When my plumber installed my new vanity faucets, he showed me that if we didnt' install and tighten the teeny-weeny screw in the side of the hot water handle and the cold water handle, they could be easily lifted up and off to clean that area. I'm so glad we did that. It's a breeze to clean what is normally a tight little area. That said, I'm not sure the best approach for the calcium. What about steam? Would that work?
Lynn

I tried the white vinegar. I poured some on a full strength, waited 15-20 seconds, and scrubbed with a tootbrush. The first pass removed most of the calcium build up. I did two more passes, and it was completely clean. You have to get very close and look behind the faucet to see a slight residue. At normal viewing distance it looks clean.

The biggest problem is the faucet has a 4 inch spread which makes it impossible to fit your fingers between the handles and the spout. A small tootbrush barely fits.

I was a bit nervous about putting straight white vinegar on granite. I figured if I could eat white vinegar, and not do damage to my digestive tract, then it probably will not damage granite.

I am in the process doing the master bathroom vanity. I am going to get an 8 inch spread faucet in order to make cleaning easier.

Vinegar is a weak acid that works great for removing calcium deposits from water on dark natural stone, but make sure you don't use it on marble or light colored stone unless you've tested it first on a sample. If your stone contains calcite (the main component of marble and limestone)the vinegar or anything acidic will etch the finish permanently after just a couple of minutes.

Granite is the preferred choice of people that demand quality appointments throughout their home. Easy to Maintain because it is a solid surface that can be wiped off and cleaned up with very little effort, people chose granite as an ideal finish in their home. The hardened granite Milwaukee homes use keeps germs and bacteria from growing and can be easily wiped off with an antibacterial cleanser.

Huh?

Try simple green stone cleaner or method daily granite cleaner. Do not use vinegar!