Algae ID

Bpb · Sep 17, 2022

Been in the hobby a while now. Haven’t had this in any of my tanks before.

It’s not fuzzy, it’s encrusting, like the purple coraline you see everywhere. It’s not soft or slimy. It doesn’t even brush away with considerable effort. It’s not black liver sponge. It’s not cyano.

Any ideas? It’s almost like coraline, but black.

Jekyl · Sep 17, 2022

@vetteguy53081

Uncle99 · Sep 17, 2022

Coralline isn’t always purple.

vetteguy53081 · Sep 17, 2022

Bpb said:
Been in the hobby a while now. Haven’t had this in any of my tanks before.

It’s not fuzzy, it’s encrusting, like the purple coraline you see everywhere. It’s not soft or slimy. It doesn’t even brush away with considerable effort. It’s not black liver sponge. It’s not cyano.

Any ideas? It’s almost like coraline, but black.

Pic a little fuzzy to fully see and confirm but my suspicion is dictyota humifusa which as you described is a difficult algae to lift and can be done with assistance of a dental pick in a container of tank water and lifted off surface. This type like other dictyota which are soft is firm almost like its been superglued to surface.