Okay, so I feel like I need a better substrate for my tortoise. Currently, it's just coconut fiber. There are a few problems I had with it, though. First of all, I feel like she is getting buried in it when she walks. Also, sometimes she "bulldozes" over her food dish when I feed her and the coco fiber sticks to the wet leaves, and then she eats them. I'm worried that she is eating too much and I'm also wondering why she does this. Is there a better substrate I could use? I was thinking of buying half top soil and half play sand. Do you think that'd be better? Thanks!