I have a 75 gallon tank which is only 6 weeks old. Currently there are 3 fish and 12 Margarita snails living in it. I am experiencing my first algae bloom, brown algae. The snails are doing a great job cleaning the LR and the glass, but I am still having a algae problem on my crushed coral substrate. What type of invertebrates to I need to get to clean this up? Do I need more snails, hermit crabs, or some other type of invertebrate. Any suggestions?