Concern regarding my box turtle’s water bowl

[Maria_Z]

This morning I was checking my baby’s water bowl to see how full and dirty it was when I noticed a blackish stain. I then grabbed a wet towel and began to scrub at it. A blueish blackish color was left on the towel but the stain was still left on the bowl. I’m not sure if it’s something like mold or fungi. Or if it’s deadly or dangerous for my box turtle. I’d appreciate it if y’all could help me out.

 

[Maggie3fan]

I don't see anything that could be dangerous.

 

[TammyJ]

I can't see the entire bowl.

 

[Ink]

You use a large clay plant saucer. Safe and easy to clean. That's what I use for my box turtle.

 

[ZEROPILOT]

You use a large clay plant saucer. Safe and easy to clean. That's what I use for my box turtle.

Yep. Those are fantastic