Originally Posted by moxieberry
I would suggest a litter tray that can go underneath the wheel, which can be instead of or in addition to the corner one.
Actually, if you already have a Carolina Storm Wheel, it already comes with a litter tray, so theres no need for the corner litter box, your little one will mostly just use that as his general potty area when not running if you can successfully litter train them. Some hedgies will get it, others will just go wherever they want
As for litter make sure its non-clumping and something that cant get caught in the hedgehogs genitals. Moxieberry made some excellent suggestions