I have a few bubble corals in a group on the bottom of my tank on the sand bed. Been there a few months and they just never open up and look great. Water param are all good. Alk 11, Ca 400-450. I have been feeding the tank a variety of things but recently moved to spot feeding individually. They are under 4 x 400w MH plus PC actinics and pretty low flow at the bottom. Anything I should use specifically to target feed them? I started to use mysis, coral frenzy, cyclo, zooplankton, etc for most of my LPS. Anything else I can do? Thanks for the help.