What shape is it? Long and stringy? Flat against the glass and decorations?
The snails and crabs you already have will eat a wide variety of algae, but the best way of getting rid of algae is to not give it a source to grow from (typically excess nutrients in the water).
RO water and reduced lighting time will help. Also, you can setup a refugium and put in some Macroalgae to take away some of the nutrients that the microalgae needs.
