From memory I don't think that fake carpet and fake grass don't make great substrates, I used fake grass for awhile, and boy was it a pain to clean. Often had to soak it overnight, as you can't spot clean it.
Also lizards will sometimes get their claws caught in carpet or fake grass, which if they can't detach easily is pretty stressful.
I would recommend a lose substrate or newspaper, for hygiene and easy cleaning.