Purple-UP 8 oz, Coraline algae growth accelerator from CaribSea. Purple-Up is a new pink and purple Coraline algae growth accelerator. Since Purple-Up is not a fertilizer, it does not promote the growth of nuisance algae. How does it work? Purple-Up uses a unique dual method approach to coralline algae acceleration. It contains ionic calcium which immediately raises dissolved calcium levels in your aquarium water. At the same time Super Sea Calcium (a 10 micron aragonite powder derived from natural seawater) targets the live rock surface. Super Sea Calcium dissolves in situ; delivering calcium, strontium, magnesium, and carbonate right where it's needed. Purple-Up also replenishes iodine; an essential element for coralline algae tissues that quickly becomes depleted in closed systems. Purple-Up is an excellent addition to any aquarium with stony corals too! One bottle of Purple-Up replaces the typical multi product recipe for successful coralline algae growth favored by advanced aquarists.