Sand Bath Set Up?

[KatiePillow]

Just watch out, one of my dwarfies likes to poo in his sand bath..then roll in the sand *sigh*

[Faerydae]

I use supreme science bathing sand for mine at the moment, mainly because it's all the little pet shop near me has... but they charge £3 for a 1.5 litre box which really isn't very big :/

[Holly's Mum]

OK I've now bought some sand to make a sand bath for Holly - how deep does the sand have to be?