I use Orchid Bark. My wife and I spot check the cages in the morning and evening. After removing soiled bedding, I occasionally add new bark. But every 6 to eight weeks I discard everything and put in fresh. When I do a daily cleaning we thoroughly clean the localized area on the bottom of the cage to remove any urate or fecal matter that may be stuck. When it's time for a complete replacement I thoroughly clean the inside of the cages.