I have recently discovered that cleaner shrimp (skunks and pepps) make an excellent cleanup crew and may even negate the need for other cleanup crews such as snails and crabs. They do less harm than crabs can and will not flip upside down like snails. It makes sense that if you remove the source of nitrate (uneaten food and other detritus) you remove the fuel for algae and therefore don't need snails and crabs. For your tank I would suggest 2 skunk cleaners and 4 peppermint shrimp. Or to save money just 1/2 dozen pepps.
Good luck!