libra doser

So I have an all coral tank as of right now and out of the blue I noticed a strange growth behind my frogspawn. I don’t know weather this is dangerous or if it is some sort of coral. It is colored purple/blue with orange dots

Bought this a few years ago as an impulse buy from Bulk Reef Supply and never used it. $449.99 plus free shipping to the lower 48. I'm going to just continue to dose by hand or possibly use a Lifereef Calcium reactor I acquired off of Craigslist recently. I paid $639.99... ugh Let my...