Also Tangster wrote that Kogle could dump bleach in the entire system, would taking out livestock, then leaving the rock and sand in there work? Treat the entire system like your nuking rock... run bleach for a couple days, freshwater soak for a couple days, baking soda soak a couple days, then let it all dry out?? This would make sure that ALL algae spores in ANY part of the tank would die. Pretty hardcore, but couldn't it be done? It is going to be a hardcore process no matter what is done.