Cleaning Toto toilet

My toilet (less than 1 years old) already has a build up on it. What can I use to remove this buildup/discoloration? Is CLR ok?

I used CLR on my Coffee pot and got rid of the Calcium great.
I used CLR on my sisters toilet Orange/Red streaks and did nothing.

But CLR is fine to use with toilets, the only thing you need to worry about is abrasive cleaners if your toilet has a high gloss glaze as it will scratch and then you will get dirt buildup in the scratches.