I have a very shallow sand bed (~1/4" or 3/8" deep) in my 30 gallon frag tank. I definitely need a bit of natural help keeping it cleaner and was thinking about getting several Nassarius snails. Will they be okay with such a shallow layer of sand? Any additional or alternative CUC suggestions for keeping sand (specifically) clean? I don't want to use fish like diamond goby as I will have some coral on the sand bed and don't want them constantly being covered with sand.