The soft corals are generally much easier to keep than the hard types, and some can grow within the aquarium to such an extent that they need to be pruned back from time to time. The growth rate is rapid compared to the hard corals. Without a hard calcareous skeleton to produce the requirements of the soft coral are nowhere near as demanding as the hard corals, so they are much more suited to the beginner, or the marine tank keeper without the time or desire to cosset the corals in the reef aquarium.
Knobbly Toadstool corals are one of the leather coral species. When their polyps are fully extended this soft coral can look very much like an anemone. Being plankton feeders it is necessary to address the need to occasionally introduce some suitably fine suspended food to the reef aquarium for them to catch up with their tiny eight-armed tentacles and pass into the body of the animal.