It's LPS, not a soft coral

The main problem will be water quality - it requires twice a week feeding, 1-2 ocean plankton to each polyp (it seems, that everybody agrees, that every polyp should be fed, or it will die - I just don't want to risk and follow routine).
Has very bright color, comes in yellow, orange, greenish-black and rare red colors, quite hardy (IMHE), looks good in actinic-lit low light tank:

in usual tanks too - daytime shot:

Mine is now in a big tank with the fish, fed 3x daily - opens every time after feeding to catch leftovers.
When buying, try to choose the "meaty", or plump coral, like this:

not with the the thinnest skin, covering the sharp edges of skeleton.
The good article is here
http://www.ultimatereef.net/forums/s...d.php?t=195870 , Tubastrea - Everything you want to know.
Feeding tactics:
- if opens polyps to feed - give the food (thawed mysis, ocean plankton, something of this size), by turkey baster, ot tweezers, by hand, by syringe, attached to the rigid air tubing. Flow is off during feeding. If you make web search on feeding
sun coral - there are a lot of illustrated threads by different people.
- if don't opens at beginning - may try to remove it in a separate container and add food there, let the coral to be in contact with food fo may be 40 min (cover from the bright light, mix the water time from time and watch for temperature of the water - it drops pretty fast in the winter, may want to use one container inside the other, with the warm water in-between). Should open to eat. After finishes - return to the tank. Container feeding:
- some prefer to cut the top of appropriate-sized bottle, and use the top half to cover the coral, and feed it inside. Then remove cover.
With time it spawns (the video is on LPS forum, thread like "Sun coral spawned"), babies attach themselves to the rock, start to grow side polyps, making own colonies:
Eventually, if the tank has sufficient filtration and nitrates and phosphates reduction, it should look like the tank of Daniela Tornsten, pdf file in the links below this article:
http://www.marineaquarium.nl/februari-2006english.php
Similarly looking coral, but branching, is Dendrophillia, more rare.
Compatibility: non-aggressive, can be stung by hammer of frogspawn (or other stinging corals), no problems with xenia, mushrooms, capnella, gsp, bsp, yellow polyps (without touching). Not reef-safe fish (Chaetodermis,
valentini puffer) tried it once, then left it alone, no concequences of any kind. Tolerates bad water quality, temperature drops in case of power failure - a week ago it was 73F in the tank for hours.
The only problem is the keeping water quality.