Pink spot

So i have a small pink dot that is on the inside of my glass and it wont come off no matter how hard i use my scrubber or the magnet. What is it??

 

coralline algae, the only thing that gets it off is a razor, but it's a good thing. A lot of people let it cover the back of their tanks so that they have a purple background instead of the generic blue or black.

 

And just like any algae it eats nitrates and phosphates. It comes in many colors.

 

ok awesome wasnt to sure and wanted to get some input. Will my turbo feed on it if he goes over it? And you said let it cover the back. What if i dont have a background? its just clear and the wall is white.

 

my atreas never ate the coralline on my glass, my cowrie picked some of the green coralline off my glass though but not much of it, urchins will eat it which is one reason I dont want one, Id scrape it off the viewing areas and let it cover everything else.

 

It is an urchin magnet. They will eat all of the coraline off.