Are these Diatoms?

[roblox84]

I have been battling this algae for a few months now and at one point it got pretty bad but has subsided a bit. I cant tell if these are dinos or some type of cyano? It looks like it’s a fuzzy brown and it growing on the back wall and rocks. Can anyone tell what it is?

 

[roblox84]

Changed light color to whiter, looks a little greener on the rocks back the stuff on the back wall is mostly brown.