I make sure my tank gets fed enough to sustain the snails as well as my newly aquired fish. The snails are amazing to watch as they come right up from underneath the sand the second you place food in the tank so I would say yes place some food in the tank for them (but thats just me)
there is always some extra when i feed tht falls to the sand bed. thats what the snails and hemit crabs going nuts over.. i do not try to directly feed them.. they eat scraps