Shell rot?

[brian4342]

Hi guys, well I've started to notice something strange happening with my tortoises shell, ( its happening to both of them) not sure if it's them growing or something bad like shell rot.
Please see the pics and let me know what you think it might be
Thanks
Brian

 

[JoesMum]

They're growing fast. Not a problem IMO

 

[Eweezyfosheezy]

They look great!!! Its definitely from them growing.

 

[brian4342]

They're growing fast. Not a problem IMO

Well that's a relief
So what happens with the shells then when they grow? I'm kinda new to tortoises

 

[JoesMum]

A bit like trees, each individual plate grows a new ring. Unlike trees, you can't count rings to decide age!

The new ring is always very pale, if not white. As the tortoise gets older the older the new growth changes colour and you'll get a new pale growth ring