Is this Diatom or Dino?

[Subnautica]

Growing on glass, rock and sand bed. Brown color. Hairy look. No bubbles at all. Tank is 6 months old. It started with cyano, then went away after I treated with Chemiclean. Shortly after, this thing popped up. I put Phosguard in and see how it goes.

How do I treat it?

 

[BloopFish]

It's been said that phosphate removers such as phosguard can actually contribute to causing a dino outbreak. Although I personally don't really know if that's dino - it's lacking some obvious signs of it being dino, but it might be because it's not large enough.