Diversity and there’s no mimicking real live rock. Cultured rock has spent a few years developing, but that’s nothing compared to the real thing. You only need a few pounds to reap the benefits, that’s the magic of real live rock. I know I’m splitting hairs here, but ask anyone who’s been in the game since the 90’s and you’ll probably get the same response. Especially since people are willing to spend hundreds on a tiny nub, while LR is the backbone of any successful system. But don’t get me started on DSB, they’re the real super stars of biology.