It's concentrated urine, not poo. I'm not sure about harmful or not, and I don't think anybody has ever brought up that problem. Is he hydrated enough? And fed a variety diet? Just thinkin here...
He gets a daily soak, he feeds on weeds out of the yard every other day and he gets a mix of romaine carrot turnip green and kale with cucumber, so he's hydrated properly and fed right....so it doesn't make sence.
It's reasonably alright as long as the urates are creamy, not gritty when you feel them. I also have a tortoise that I soak daily and have for over 3 years. He has abscessed sinus's. He also has thick gritty urates. Go figure...
Have you tried to place a cuddle bone in the enclosure with the tort? Perhaps the tort is trying to get some additional calcium????? Just thinking her along with Ms Maggie