purlpe algae?????????

[goinpostal]

i was looking at some pictures on this site and saw what looks to be a purple film on the back of the glass is it algae and is it bad to take that off the glass

 

[WarOrks15]

not bad. it is coralline alage. it grow under good lighting. most people let it grow all over but the front and may be the side pains of glass. but if you give it a long time to grow all will be covered in it

 

[two11devan]

Yea, the whole rear and one of my side panels is completely covered in it. It gives it a nice natural looking backdrop. But boy is it a pain to keep scraping the front and other side of the tank! If what you have is coralline, its a good thing and some people would kill to have it in their tanks!