Tubastrea spp., as well as pretty much all stony corals are carnivorous. They will not touch phytoplankton. I think 5vexy's feeding regime would work great for any Tubastrea spp. I would try to target feed them, unless you are feeding those foods to multiple corals, then I would let it spread throughout the tank. At least that way, you would save some water quality in the process. You have to be careful listening to LFSs sometimes.