Hey Ashley,

This is coming a little late...but those "stress" circles you were seeing, aren't a big deal. On some dragons they show more than others and they can also be temperature related. My beardie tends to get them every afternoon. In the morning he's yellowish and by the evening he's rust colored with dark circle outlines on his belly. They tend to darken up when trying to absorb heat more.

I'm also in favor of tile. I love mine. It's so easy. Once a month I bake it for half and hour, otherwise just spot cleaning. Some people love reptile carpet, apparently it can go in the washing machine, so it's just recommended to get two that will fit your cage.

Keep in mind that full grown beardies are fine on playsand (not calcisand), so if you want to switch over to sand when they are over a year, that's perfectly ok.