Flower pot coral usually refers to either goniopora or alveopora. They have 24 "pedals" and 12 respectively for identification purposes. They are both very difficult to take care of and have a very poor success rate in home aquariums. Here are a few bits from a coral book i have that might help you give it the best shot.
"recent research suggests that almost half the food taken by goniopora in the wild is phytoplankton, and the rest very small zooplankton."
"goniopora are strongly aggressive corals and can easily sting nearby specimens with their long, flowing polyps. The normally prefer medium current flow and medium to bright light, as they are often found in lagoons in the wild."
"Feeding goniopora is likely to be required, because the energy provided from photosynthesis is not adequate for their daily energy needs. Many goniopora, however, have not been seen to capture prey in captivity, so absorption of nutrients or unknown food sources may be thier primary method of heterotrophy."
"because of the hydrodynamic drag of the long polyps, goniopora should be firmly attached if placed up on the rockwork, lest they become vidtims of "falls" caused by water motion or other disruption."
That was all from "aquarium corals" by Eric H. Borneman for copywrite purposes.
Because when feeding phyto and zooplankton though. They can increase your nutrient levels in the system rapidly causing problems with algae quickly.
As the others have said. Frogspawn and duncans will still thrive with out any supplemental feeding.
You have a challange on your hands and i would not recommend even the most experience reefers to try the flower pot corals as we just don't seem to be able to understand them and provide for them yet. Not trying to take a shot at you or seem like i'm nagging. Just trying to give you the best shot at keeping your coral healthy.