Large Polyp Stony Corals are generally larger calcareous corals with large fleshy polyps. The degree of extension of the tentacles depends upon the amount of light, current, and whether the coral is feeding or not. Most of the LPS hard corals produce long sweeper tentacles which they use to keep any other organisms a safe distance awa

Mushroom corals are hardy and make ideal corals for the beginner reef aquarist. Mushrooms that have long tentacles are aggressive toward other types of corals, so provide these corals with adequate space.

Polyps are colonial corals, and most of them are extremely hardy, making them ideal candidates for the beginner reef aquarist. All Polyps contain symbiotic algae and require moderate to strong lighting. Some Polyps, such as button polyps, will also benefit from meaty food such as brine shrimp or plankton

Sea Fans are similar to soft corals, however, they anchor themselves in mud or sand instead of attaching themselves to hard substrates. Some Sea Fans require up to 8 inches of sand. Most Sea Fans are nocturnal, only extending their polyps during the nighttime hours. They consume plankton and require strong currents to carry their food.

In reef aquariums, it is important to leave adequate space between different species of hard and soft corals to avoid problems with growth or aggression. Most soft corals grow rapidly in reef aquariums, and are relatively hardy corals for the inexperienced reef aquarist.

In general, the Small Polyped Stony corals have small polyps on a calcareouss skeleton. In many instances they are either branching or plated. SPS hard corals are generally considered more difficult to keep than the LPS or soft corals and are not recommended for beginners.