Most of he time I would wait until the chameleon started digging in the laybin in the cage befor moving her to the big container ...that way I'd know she was ready. However...if I thought she might not like the laybin in the cage I would move her to the huge 65 litre rubbermade container that I had modified. The thing is, IMHO once you move her you need to leave her there rather than moving her back and forth. The modification to the bin was cutting a huge hole in the lid and screening over it so the UVB light could be put on top of the lid on the bin. I added a plant, branch and filled the bin about 15" deep with washed play sand. The chameleon couldn't escape, could be watered by hand mister sprayed on the plant and sides of the bin, fed as long as you removed any excess insects, etc.