Lighting is deffenetly one of the causes to the growth of the green algae. Is it micro (growing on the glass) or macro (long hairy stuff on the rock work) algae? I had a huge algae bloom first on the walls then throughout the water. It has since cleared up with the help of snails eating the stuff off the glass, rocks, and sand and doing frequent water changes. I only have a frag of green mushroom coral and the snails in the tank so the bio-load is low right now. Sometimes with new tanks it is part of the cycle and once it passes you can ease up on the water changes to a normal amount. My tank is a 24gall aqua pod and I was doing about 25% water changes 3-4 times a week for about 3 weeks. I have since dropped down to 1-2 times depending how lazy I am with lots of testing (I'm strict about my tests). If it is hair algae then there are dwarf hermits, such as the Dwarf Blue Leg Hermit, that are omnivores that can help with the problem. I know the Lawn Mower or Algae Blenny will eat all the hair algae but according to LiveAquaria.com they need 30galls but someone here might have experience that says otherwise. I have not owned one yet so please don't think that I'm suggesting one. Best of luck and hang in there, going slow is key to everything and will save you lots of money and aggravation later one.