On Fri, 24 Jul 2015 17:00:34 -0400, J Burns
wrote:

On 7/24/15 2:29 PM, Muggles wrote:
I have this stubborn calcium deposit stuck to my toilet bowl, and I've
tried everything I can find off the store shelves that I'd normally
clean it with and nothing seems to work. I actually got some of it to
chip off, but it's a pain to even get that to come off. Is there
anything safe I can use that'll dissolve the calcium deposits that isn't
a nasty acid of some sort?

-- Maggie

What a coincidence! I bought a cheap low-flow toilet 19 years ago. I'd
use CLR and and the kind of abrasive pad that looks a little like an air
filter, to keep the rim clean, but it was only a few days ago that I
paid attention to the dark stains at the bottom.

I waited until I wouldn't need the toilet for a couple of hours. I shut
off the water, flushed, shoved in a brush to push some of the remaining
water out, and added a maybe 1/2 ounce of CLR. When I came back and
brushed, dark cloudiness showed it was working.

I discovered that 15 minutes after shutting off the water and flushing,
the bowl might be full again. Without much water in the tank to press
the flapper down, I guess it can seep.

I repeated it whenever the toilet would be idle for a period of hours.
Sometimes I used CLR and sometimes vinegar. The cloudiness when I came
back and brushed showed that they both worked.

That cheap toilet has a corner at the very bottom. That was the last
spot to come clean. Some recommend muriatic acid, but I'd be afraid of
pitting the glazing.

If the flush "throat" passage (my term) is not glazed in the toilet it
is a valid concern. I've not had a problem with MA in my former
rental homes or those I detailed for real estate agents.

MA has never harmed a glazing in a modern toilet, YMMV.