It looked like snot with a white spot in it that was yesterday, today he did it again in his soaking container and it looked like egg drop soup egg whites in it. But just one chunk tho.
Was the white stuff kind of like toothpaste ?
If it's not gritty, it's probably okay, just urates in thick solution because the tortoise is trying to conserve water.
The tortoise probably needs extra hydration, more and longer soaks and ensure it has access to plenty of drinking water, sprinkle water on the food also.