I'm recruiting a cleanup crew for a 16G and I've read this ode to the Tuxedo Urchin. They are "guaranteed to vigorously graze a wide assortment of algae".
My idea for the 16G clean up crew is:
For algae: 1 Tuxedo Urchin
For uneaten food: 1 or 2 nassarius snails, 1 or 2 astrea snails. (Do I need more?)
Would one tuxedo urchin do well in a 16G, keeping algae under control? I assume more than one would starve in a 16G.