<a href=showthread.php?s=&postid=13351584#post13351584 target=_blank>Originally posted</a> by UrbanSage
New coralline will in time grow on top.
I think (without having looked into it) that coralline will turn white if still exposed to water.
I have several old powerheads covered in pink that were removed from the tank, these powerheads are still as pink as when I took them out.