Growing around overflow - good or bad?

I noticed this stuff today that growing between the 2 layers of the overflow.. I have no idea if its good or bad or what to do.. You can see some is bright green and some not.. Look between the slats in top overflow













I did best I could to get good pics...

 

Are you talking about the little splotches around the teeth of the overflow? if so,that looks to be coralline algae,if so,it's a good thing.What color is it?Coralline usually attacks plastic quicker than rock,so it's probably the first signs of starting to spread.


Edit-I had a closer look,and I think I see the green stuff your talking about,probably algae.But what kind? IDK

 

+1 to splotches looking like coralline and being ok. The other stuff looks like algae, do you have chaeto? If it were me,IMHO I would clean the green stuff out of the teeth, haha. I don't like stuff in there that can impede the flow into the overflow box. Also don't like the idea of algae going down my overflow, possible clogging things and causing a flood.

 

Thanks... Will clean it

 

need to cover it...you really do not want nuisance algae growing in your overflow..imo
I just got a piece of thick ( 1/8 ) rubber and cut it out to fit over the top...just sets there by its own weight.
No light inside mine...but coralline grows on the DT side no worries.

 

Sits on the small ledge between the 2 pieces? that space is about 1/8" i guess.. I dont need to cover the rest of the overflow area just where light can get down between the little space right??? I am trying to figure out how and what to clean the space with - any suggestions

 

just dont want light goin in there ...it will die of when deprived of light..no worries. : )

 

Very smart suggestion! I've run my reef for over 4 years now and never thought to light block the overflows... This is why I love this forum! Just ordered a nice heavy rubber sheet ;D