I was using Carefresh, but it IS messy and expensive, so I switched to fleece. Since I've built them big cages on the floor, I don't use choroplast; I put bath rugs on the floor, a couple (or more) layers of fleece and felt/uhaul, then one big piece of fleece on top. just pull the piece of fleece up around the sides and in some places I clip it to the grids. I'd LIKE to use the choroplast around the edges, I even bought some, just don't know how to cut it to fit. My eyes and hands aren't the best. The fleece+ gets mounded between the 2 cages a little and I put large cardboard or choroplast pieces between the grids and the room walls. It's not comfortable to clean, but then the smaller cages weren't either and they weren't on the floor. This way is best for the little ones and they love them, so... I change each cage either every 4-5 days (Scatter & Flossie) or every 3-4 days (Peek, Fuzzbutt & VeBee) or when the cage starts to smell. I don't mind smelling hay, but barnyard scented house is NOT on my list of favorite perfumes, lol.