These are often incorrectly called a scoly. Formerly called Cynarina Deshayesiana.
The current, correct scientific name is Acanthophyllia Deshasyesiana.
Typically the meat coral sold in any lfs is anywhere from 3"-6". However, most Deshasyesiana grow up to an average of 8"-12". I have heard of one reefkeeper "Seapug" whose meat coral had grown to be 12". Apparently some days when the water parameters were just right for it, it had spread to 18". So they are typically medium/easy to keep and grow if it has lots of room. It seems to prefer a sandy bottom to live on and spread out.
Make sure to keep this away from other corals because it will lose the warfare. It's a more passive coral in that way.
Care Level: Moderate
Tank Placement: Bottom to middle
Water Conditions: 72-78 degrees F, dkh 8-12, ph 8.1-8.4, sg 1.023-1.025
Suppliments: Calcium, Strontium, Trace Elements
Meat Coral is one of many common names used in describing Acanthophyllia deshayesiana, but this is an apt title, as this species has a thick and fleshy polyp. Their fleshy skin is rather delicate and care must be taken when placing them in the aquarium so the thick, toothy skeleton doesn't cause too much damage to the soft tissue. When the soft tissue expands, it drapes dramatically over the edges of the skeleton. Color may vary from red-brown to bright green or red, and, in some cases, specimens may be striped or mottled with another color. Place these corals either low in the tank or firmly anchored midway up in the tank, with low water movement. They do produce food through photosynthesis, but will also except an occasional meaty foods placed near the oral opening.
While it is not an aggressive coral, it should be provided with adequate spacing between itself and other corals because it can expand to twice its size. It is easy to maintain in the reef aquarium and makes an excellent choice for both the beginner or advanced reef aquarist. It requires medium lighting combined with low water movement. For continued good health, it will also require the addition of calcium, strontium, and other trace elements to the water.