that's so amazing it wasn't bleach. a beer, of all things wow. not harmful agreed, my own reef could take a guiness and not even burp. carbon me up another round ol chap, and this time with some zest, it would say. clouding and some algae bloom worst up I bet. when I read the title I thought she'd have gone for the classic bleaching move from laundry closet. luckily, even if those aren't overdone / survivable...then in the least she might have killed off some invasive dinos pre-emergent.