My newest acquisition is a half inch green spotted puffer we have named Green Goblin. I know that a majority of his diet is going to have to be crustaceans. I want to set up my 3 gallon tank to breed some snails to feed him. Figure this will be easier then going to pets mart all the time. Do I just throw a algae covered stone, a filter and a heater in and then change water weekly? What else would I need for them?