I have recently bleached some rocks and added them to my new tank. They had pink and purple and maroon coraline algae growing on them but the maroon color quickly outgrew all the rest of them. Will the pink and purple grow back over the maroon or am I out of luck? What should I do to keep primarly the colors of coraline algae that I desire growing fast in my tank without this maroon outbreak. The rock I started with had more pink and purple on it than maroon. Thanks!