I have been cycling my tank for a few weeks. My ammonia and nitrite has been at zero for a week. I have a outbreak of green hair algae and can't get my nitrates to go below 20ppm. I have live rock from the gulf and dry cycled rock in the tank. Will bio spira help get my nitrates down so I can get a clean up crew? I have done two 50% water changes on my tank and even changed my filter sock twice.