LPS and SPS are acronyms for Large Polyped Stony, or as some would rather say, Large-Polyped Scleractinian and Small-Polyped Scleractinian. Sceleteria refers to stony or hard corals.

The LPS corals among the most beautiful corals because of their fleshy texture, colors, odd sizes & shapes, and that they move and sway in the water currents unlike the SPS corals.

The SPS corals are the primary colonizers and fundamental reef builders. They have incredible growth rates. Their skeletons create the backbone of the reef structure and are what our live rock is made of. Tonga and Marshall Island live rock is composed of mainly dead Acropora skeletons, while Fiji is composed of massive Porites, Favites and Pavona. It was not long ago SPS corals were thought to be impossible to keep in an aquarium.

The terms LPS and SPS are not a scientific terms. "LPS" refers to all hermaphytic sceleterian corals that have *large* fleshy polyps. "SPS" refers to all hermaphytic sceleterian corals that have *small* polyps and corallite structures. The term small is extremely subjective. Different hobbyists have different opinions on what small is. In general SPS means any sceleterian genus that contains polyps smaller then 5mm.