My tank had some sword leaves that had turned white and puffy. I assumed they were dead and moldy, but when I went to pick one, I discovered that it was actually encrusted in some sort of hard, almost coral-like substance.
Does anybody know what this is? Bryozoans seem to be the only thing I can find on a search that might fit, but it's not slimy at all.
And what are the implications for my tank? Is this neutral from the standpoint of the fish?