I have a sand bath for Zero, he absolutely loves it, and uses it as his potty, every morning I clean out all the poop (who knew a little dwarf could poop that much!
) and try and get the clumps from pee. How often should I completely empty it and fill it up with new sand? It is starting to stink a little, so mabye whenever it starts stinking? I don't want it to be unhygienic.