They are well known for dying in captivity. It appears to me that luck is a huge factor in success. I dont know why but Ive had good luck with them. I dont do anything with it care-wise. Just watch it ellegantly wave in the current.
flow should be med. and random. very fine food could be used and it just needs to fall on it. the food i put in the tank for them is called Reef Roids. you can use another thats called Snow i do beleave. flower pots are kinda touchy. i have had mine for a year now and it lets me know when my salinity is low. i think they like the higher salinity like in the 1.026 or 1.028 range.
Generally speaking there are two main types of corals referred to as flower pots. The goniopora which has 24 tentacles per "flower" and the alveopora which has 12. The alveopora is somewhat hardier. Without specialized and attentive feeding both will wane within a year.
Some varieites of goniopora are a bit hardier than others with the small polyped reds seeming to be the most hardy. I would not recommend either goniopora or alveopora unless you have studied them well and are prepared to employ special feeding techniques.
If you have fish in your tank ,.euphylia, such as the frogspawn, hammer and torch will not require specialized feeding. Most corals like a bit of cyclopeeze from time to time though.