I feed my gobies daily with mini krill, pellets, cyclopeeze granuals, frozen food... I mix it up so they don't get used to one type of food... my sand was 3 1/2 all around but now 5", 4", 3" and 2" at other places...
They WILL reorganize your livesand to what they want.. now they have it to where they like it and don't move as much only sifting now...