Thank you so much.
I'm really glad I posted as it's an absolute nightmare looking online and in books as they have even mentioned shell rot, eveb though appear to be aimed at the British market.
Thanks again.
If you don't mind, are supplements needed in the UK?
We've recently taken over care of this tortoise.
I noticed a couple of days ago the white patch. I can't say how long it's been there for. But of course, as soon as you type this into any search, first responses are shell rot.
We're UK based, and they have lived outside all of their lives - 45...