Acanthastrea
Another species that Acanthastrea has lost in recent revisions is A. bowerbanki, now Homophyllia bowerbanki, whose situation is similar. In addition, the genus has gained the species Acanthastrea pachysepta, formerly Lobophyllia pachysepta. Other known species, which (still) belong to Acanthastrea, are for example the flat growing Acanthastrea echinata, which grows similar to Chalices. Furthermore there are species of little importance like A. ishigakensis, A. brevis, A. hemprichii or A. minuta, which are normally not commercially available. Acanthastrea are hardy corals that are less demanding on water quality. But you should keep an eye on the carbonate hardness, because they easily get weak if the level is too low - in our aquarium a level above KH 8 has proven to be good.
They need nutrient-rich water with clearly detectable phosphate and nitrate, or active feeding with powdered food, frozen food or LPS pellets. They are more colorful when kept in lower nutrient conditions, but they are also very susceptible. Acanthastrea are often found in colder water, sometimes even dropping below 20°C in natural sites, and often become more colorful in colder aquarium water than at higher temperatures. They require moderate current and only rather dim light, otherwise they will become distressed and burn.
When it comes to lighting for Acanthastrea, a high blue light level not only leads to better fluorescence, but also leads to better coloration in the long run. Most popular are the "Acanthastrea" lordhowensis, also just called "Acan Lord" because it has the most extreme color morphs. Gray-purple and green are very common, red uncommon, pink rather rare and very rarely yellow or orange variants. Many suppliers divide Acanthastrea into "Grades" going from normal to "Ultra" or "Rainbow". So the "Rainbow" or "Ultra grade" Acanthastrea are the absolute best colored and rarest individuals, often with yellow/orange and several other colors at the same time.