
Soft Corals and Polyps have around 2,500 species known and the specie are highly diverse in appearance. Some resemble anemones whereas others will grow to huge structures. The majority of of species that will interest aquarists will contain symbiotic algae and will need plenty of lighting.
Soft corals and polyps will influence their neighbours by either sting them or by releasing noxious compounds from their tissues. To prevent a single specimen from dominating the aquarium, you will need some form of removing the noxious chemical from the water, generally a protein skimmer will do the job.