I feed many (not all) of the polyps if there is interconnecting tissue between them.
Single sun coral polyps not connected to a colony are required to be individually fed.
I feed mine primarily frozen mysis shrimp and target feed them one by one in the main
tank. Initially, though, I did remove them from the tank to feed, but that was during
the initial stages when I was trying to coax the polyps out; I no longer do that.
Takes time, but the mysis shrimp is soaked and swished in cups of RO/DI water (three
cups of RO/DI in succession to reduce the level of phosphates prior to entering my tank).
No algae problems.