Ran into a bit of a problem with the Buddha head. I took it out to clean what I though was algae growing on the face. Lightly scrubbed it with a toothbrush and the white came off revealing a darker color underneath.
I thought the stone was naturally white but it seems it was some type of paint or coloring, the stone underneath is a lot darker. Took it out quickly then did a 80% water change. Hopefully whatever leeched out in the 24 hours won't kill my cories....
They seem to be acting alright. Will probably continue to do some small water changes daily for the next couple of days.
An hour of cleaning with 3 different brushes and here is the newly cleaned up Buddha head, it's a bit darker: