What am I dealing with?

[TLO45]

Curious what everyone thinks this is?

 

[KrisReef]

Reef scum, aka pain on the glass.
Green algae, golden diatoms, bacteria, pod & snail food, a thriving primary ecosystem.

 

[Jason Scalise]

Looks like every ocean habitat I have seen.
Snails and pods will love you if you put them to work here.
Looks to me like you have some good nutrients turning into photosynthesized algae.
Looks healthy actually.
I would not worry.