Whats this called

[Dipen]

My ceramic rings are changing from white to red like black.....is this algea or what......if this is algea how to clean to white.......

 

[duanes]

Looks like red algae to me.
There are many species of algae that are different shades of red, depends on the wavelength of light , water temp, and flow available as to which species proliferate.
One of my aquatic microbiology classes had a text book called "The Algae of the Great Lakes of the U.S., there were over 100 different species named in the text book

 

[Fish Tank Travis]

As the media “cycles” with beneficial bacteria, it will start to turn a little bit darker color, but not that dark. That is definitely algae. The best way to prevent it is to cover that part of the sump up so that there is no light for the algae. The beneficial bacteria doesn’t need light, but the algae will die without it, or not grow in the first place.