I came across this article by Chris Jury in reefkeeping online magazine.
http://reefkeeping.com/issues/2006-03/cj/index.php
A lot of good info about different corals and their ideal environment.
Here's the section on zoanthids....
Notice that this word contains only a single "o." A zoo is a place where animals are kept on display, whereas zo-(rhymes with toe) is a prefix meaning "animal." Actually, the prefix zo- and the word zoo have completely different etymologies; that they appear to be similar is just coincidence. This is a simple point, but I can't overstate how it grates on the ears of folks who know better. My advice in any endeavor would be to know the correct pronunciations of its words; otherwise we seem less-informed than we truly are.
As mentioned above for corallimorpharians, zoanthids do not need and are not necessarily healthier in high nutrient water. Tropical species often grow on the same reefs as our other corals, and there is no reason to assume that their needs for dissolved inorganic nutrients should be different than that of any other groups of corals. They do seem fairly tolerant of conditions that other corals often don't tolerate, but this is no reason to push them to their limits. They have no more place in a new, immature tank than does any other coral. Similarly, a dog might be able to go two months without food whereas a cat might only survive one month, but who would test this on their pets? It probably isn't a good idea to see how far our charges can stray from suitable conditions and still survive. Along these lines, nutrient-rich water does not satisfy all the nutritional needs of most zoanthids. In fact, many of them are decidedly predatory (Tanner, 2002) and some absolutely feast on any food offered. Other species tend to be much pickier in what they will accept. In general, species in the genus Zoanthus tend to rely heavily on light, dissolved nutrients and detritus. Some species readily take certain prey but reject many others. Finding out what they will and won't take is largely a matter of trial and error. In nature plenty of whatever they eat is usually available, so obtaining sufficient food is rarely an issue for wild zoanthids. Due to the very limited plankton populations in our tanks, this is not the case in captivity. Species from some of the other genera tend to take food more readily, especially some Protopalythoa spp. Some individuals in this genus can be absolutely ravenous, and while they use light to a large extent (like most reef corals), food seems to be more important (Tanner, 2002). The polyps of a particular colony that was in my care often would catch and engulf five or six pellets or two or three mysid shrimp at a time. Each polyp would then reopen within minutes and take the same amount of food again. I have fed this colony this amount of food four and five times a day, and it eagerly takes the food each time and expands again, tentacles waving in the current. So much for zoanthids not eating.
In terms of light intensity and water flow, luckily, these corals are very adaptable. They certainly can and do grow in modest light levels and weak water flow, and this is often what they're given in captivity. More often in nature they are actually found in shallow water where light is very strong and water flow can be turbulent. On a large granite boulder in "The Baths" on Virgin Gorda, BVI I saw a carpet of Palythoa sp. covering at least 300 if not 400 ft.2 reaching from the surface to about 2 m depth and exposed to crashing waves without any shade from the sun whatsoever. While the majority of species can be found in shallow areas, some are found almost exclusively in deeper water. Again, variation is the rule and classifying any sort of conditions as the "right" conditions for this group ignores the fact that each colony can be very different from every other colony. No two species are the same and there are likely many species (though they need taxonomic revision).
http://reefkeeping.com/issues/2006-03/cj/index.php
A lot of good info about different corals and their ideal environment.
Here's the section on zoanthids....
Notice that this word contains only a single "o." A zoo is a place where animals are kept on display, whereas zo-(rhymes with toe) is a prefix meaning "animal." Actually, the prefix zo- and the word zoo have completely different etymologies; that they appear to be similar is just coincidence. This is a simple point, but I can't overstate how it grates on the ears of folks who know better. My advice in any endeavor would be to know the correct pronunciations of its words; otherwise we seem less-informed than we truly are.
As mentioned above for corallimorpharians, zoanthids do not need and are not necessarily healthier in high nutrient water. Tropical species often grow on the same reefs as our other corals, and there is no reason to assume that their needs for dissolved inorganic nutrients should be different than that of any other groups of corals. They do seem fairly tolerant of conditions that other corals often don't tolerate, but this is no reason to push them to their limits. They have no more place in a new, immature tank than does any other coral. Similarly, a dog might be able to go two months without food whereas a cat might only survive one month, but who would test this on their pets? It probably isn't a good idea to see how far our charges can stray from suitable conditions and still survive. Along these lines, nutrient-rich water does not satisfy all the nutritional needs of most zoanthids. In fact, many of them are decidedly predatory (Tanner, 2002) and some absolutely feast on any food offered. Other species tend to be much pickier in what they will accept. In general, species in the genus Zoanthus tend to rely heavily on light, dissolved nutrients and detritus. Some species readily take certain prey but reject many others. Finding out what they will and won't take is largely a matter of trial and error. In nature plenty of whatever they eat is usually available, so obtaining sufficient food is rarely an issue for wild zoanthids. Due to the very limited plankton populations in our tanks, this is not the case in captivity. Species from some of the other genera tend to take food more readily, especially some Protopalythoa spp. Some individuals in this genus can be absolutely ravenous, and while they use light to a large extent (like most reef corals), food seems to be more important (Tanner, 2002). The polyps of a particular colony that was in my care often would catch and engulf five or six pellets or two or three mysid shrimp at a time. Each polyp would then reopen within minutes and take the same amount of food again. I have fed this colony this amount of food four and five times a day, and it eagerly takes the food each time and expands again, tentacles waving in the current. So much for zoanthids not eating.
In terms of light intensity and water flow, luckily, these corals are very adaptable. They certainly can and do grow in modest light levels and weak water flow, and this is often what they're given in captivity. More often in nature they are actually found in shallow water where light is very strong and water flow can be turbulent. On a large granite boulder in "The Baths" on Virgin Gorda, BVI I saw a carpet of Palythoa sp. covering at least 300 if not 400 ft.2 reaching from the surface to about 2 m depth and exposed to crashing waves without any shade from the sun whatsoever. While the majority of species can be found in shallow areas, some are found almost exclusively in deeper water. Again, variation is the rule and classifying any sort of conditions as the "right" conditions for this group ignores the fact that each colony can be very different from every other colony. No two species are the same and there are likely many species (though they need taxonomic revision).
