well its because they only need rocks when they are young or when really beat up.. and the deep part is because they need low ilumination..or with blue colors..but normal day light work just fine imo.
if you hace egg crate under your substrat..or tight em very well to rocks.. cause otherwise the will dug'em up
fronts are like little puppys always diging or looking for food on the sand..they are almost sandsifters..always hoovering with their ventral fins in the sand..