Since my White's made a huge, huge, huge mess in the vivarium (but some of it was my fault...I really made the soil level too low, considering how high the water needed to be), and since there were white worms I couldn't identify, I tore it completely apart and rebuilt. I think it looks much better now.
Unfortunately, Luigi has already made a mess by putting soil and leaves and dirt into the water. Oy. I may just need to use a water dish.