Vinegar, NO, how about Acetic or muriatic acid?

[banditpowdercoat]

I know Muriatic is Hydrochloric acid. I use it for eating aluminum and removing the Galvanized coatings of of metals. It will leave a residue and most likely render the tank useless.

Why not just a really diluted vinegar? I would think 5-10g in freshwater would loosen up the coraline after a few days