Coralline will actually grow over itself as well as similar strains competing for the same growing areas. If it looks alot like flaking skin, I wouldn't be too concerned about it. If anything it will help spore the tank as it flakes off and will eventually spread around the tank faster.
Might also be a sign of abiotic precip if you maintain your chem levels too high.
Not much you can really do about it otherwise.
Cheers
Steve