Carefresh is about the same price as aspen here. I didn't like the smell with the aspen.
Tami, I only use about 2 inches in the bottom as well, and I spot clean daily, and totally clean monthly, unless they're unusually stinky.
Lately, mine have taken to hiding under the carefresh and pooing all over the bottom of the tank, which makes life a bit more challenging for the cleaning crew.