Dirt,cukes are an excellent addition for a tank with a sandbed.The LFS here keeps them in those little cubicle tanks and they claim they are very hardy.I have no personal experience with them but i'm sure someone else will chime in.Buy a small one and i would think you would be fine as long as you feed your tank enough.The end result with foods after it is consumed/excreted is detritus which is what they eat.