It seems like my tank is always growing new algae, despite my low phosphate and nitrate levels, strong lighting, constant water changes, good water flow, and active carbon. Right now I have red bubble algae in my tank. Its mostly on one rock, but a lot on that rock. I was thinking about taking the rock out and scrubbing the bubble algae off the rock. Just wanting to make sure this is the easiest and most effective way. Also, my sand gets algae every few weeks. It usually turns up brown, and makes a blanket on top of my substrate. I had this when i had a red slime algae or dinoflaggelate(sp) bloom. I am just trying to see how natural this is. Or something is wrong with my tank. My tank is ready to go reef now, except I am afraid with all this algae around, harmful or not.