the easiest way to tell if liverock is uncured is to smell it. if it reeks like dead fish or the ocean in general, chances are it's not cured. if it's not cured, it will spike your levels, (ammonia), and possibly cause another cycle. many people use uncured liverock to cycle tanks, instead of damsels. pick it up out of the water and smell it. if it stinks, it's not cured. if it doesn't, it's cured. if you order liverock and have it shipped to you, it will need to be recured, even if they say it's cured. the day or two in a bag without circulation or light causes die off. HTH