Pretty sure it's Dino, trying to get rid of it as natural as possible. What would he the best natural option. Have a nano tank with no skimmer just biological and filter socks for export.
I would guess either prorocentrum or amphidinium dinos in that picture. It's a bit blurred and really low mag. If you could get another pic with a little more mag, that would help. But they don't look like ostreopsis.