Coralline Algae

Coralline algae will only start growing in your reef aquarium if it is introduced, usually on live rock. You can also introduce it with coralline scrapings from another tank or buy it from the local fish store in starter packs. Even then, it takes a month or more to start spreading throughout your aquarium and many months to cover most of your live rock. It is the goal of most aquarists to have a good covering of these algae in their aquarium.

Calcium levels need to be maintained somewhere around 400 mg/L for this type of algae to propagate. Phosphates also need to be very low.

Problem algae will not grow on top of it, and that's a good thing.

There are a variety of nice colors that exist. Red, purple, green, white and pink are know to grow so far. Usually live rock that is gathered from a natural reef will only contain one of these colors. If you desire more variety of color in your reef aquarium, you may have to introduce live rock from different sources.