Such a beautiful tank.
How to you keep that NPS happy? Are you adding anything to maintain the Oysters food wise?
NPS corals thriving on constant supply of fine particles food. Detritus is one of them, the very reason I don't have mechanical filters in the system. Blasting the sump with powerhead will keep the detritus suspended and goes back into the display as foods foe corals and other filter feeders.
As for oysters food, yes I am broadcast feeding twice a week with commercial filter feeders food. My bacteria reactors is producing constant supply of bacteria planktons as well. I am not sure how it happens, but occasionally my tank will experience phytoplankton bloom (water columns turns green). I cannot replicates the bloom, it must be happening randomly. I witnessed this phenomenon twice a few months back.