What is this stuff growing on my back wall?

[Redbird5]

Is it some kind of algae?

 

[EnterName]

I could imagine it being some kind of sponge (e.g. page 5, post 82 but less "fuzzy", or page 11, post 206 but white instead of yellow/orange). If it's growing on the back wall chances are it's not a cryptic species. Some sponges can become annoying when growing aggressively.

 

[Baldyreef]

I agree with EnterName, seems to be a sponge by that pattern and color

 

[Nate Chalk]

Is it some kind of algae?

Looks like corn, soon enough itll be knee high before the 4th of July right @fishguy242

 

[fishguy242]

Agree sponge ? can you get a clearer pic ?

 

[Redbird5]

Agree sponge ? can you get a clearer pic ?

I'll see if I can. If it's sponge I won't worry about it. That means the aquarium is healthy and mature.

 

[Redbird5]

Here's a closer picture