Reef Aquarium Coral Types

Small Polyp Stony Corals (SPS)

SPS corals get their name from the small fleshy polyps that lay down a calcareous skeleton. This skeleton is the base of every reef on the planet and provides a habitat for many other species including fish, shrimp and other invertebrates. These corals use zooxanthellae in the same way that LPS and other corals do, but they require more specific conditions to grow and maintain health.

SPS corals are very sensitive when compared to other corals and require high intensity lights (metal halides), perfect water quality and a constant supply of available calcium. Using a 10-20k metal halide bulb in conjunction with actinic T5’s or Power Compacts has proven to be a great combination for these corals. Figure on using about 7-10 watts per gallon of water for SPS corals. This is a drastic increase from the 3-6 watts per gallon for LPS coral, but the increase is necessary because of the reduced polyp size of SPS corals and the reduced amount of available zooxanthellae for photosynthesis.

Due to the reduced amount of zooxanthellae in SPS corals, it is sometimes necessary to feed the corals using phytoplankton or other coral food such as “Marine Snow.” If you are using a refugium on your aquarium, then you are probably providing daily phytoplankton, so feeding will not be necessary.

Propagation of SPS corals is accomplished by sexual reproduction as well as budding and splitting. Hobbyists will often “frag” a coral by removing a part of it and affixing it to a piece of rock. This frag will grow to become another colony over a period of time if provided the right conditions.