i'm dealing w/ green algae too--i use about 15 blue legged hermits, 1 turbo snail, 2 astrea snails, 1 emerald crab, 10-15 cerith snails, and a hitchhiker stomatellid snail--this team has been at work now for about 2-3 weeks--they are definetly making an impact
scrub algae of your rocks with a new toothbrush...use RO water...bring your tank water to the lfs for a free testing--they can give you more advice