I purchased various cleanup crew that includes 2 sand sifting stars, 3 nassarious, and 10 astrius snails. I have A Diatome bloom when i first put them in the tank, and they have cleaned the place up very nicely in my 55 gallon tank! Its too perfect. Now i am concerned that the stars are not getting enough food since i virtually have no diatomes left. The snails all eat but the starfish are starting to come above the sand more often now as if to search for food. Hope they are not being starved! What should i do?