prata and lps are not that hard to keep provided with good water quality even that some say it needs abit of nutrients in the water.
btw, they do feed in nature not just that ppl tot they just need sunlight.
normally they will eat so-called marine snow which are like the debris from the top.
Most corals get carbohydrate through sunlight and get proteins from the water.
From the water in nature, it's normally marinesnow and planktons but we dun have them in our water.
so feeding them will help them to grow faster too.
but make sure it's small enough or else u will hurt them.
even without targetfeeding, they will still grow slowly when u feed ur fishes as they are constantly filtering ur water with their tentacles.