Help with coral

Hello everyone so today I went to my LFS and purchased some more cured live rock and when I got home I noticed a sun coral and a carnation tree coral I know they are NPS and don't need light but I've read they're extremely difficult to keep can anymore elaborate thanks BTWi have a fluval edge 12 5 pounds live rock A ocellaris clown and 3 pounds of live sand I use nutri sea water so all my parameters are in check Ph 8.3 nitrite ammonia 0 nitrate 0