If the rock is actually cured, you should be ok adding it in. Be really careful digging up that sandbed tho.... I added 20-30 lbs of cured rock to my setups (92 & 100 gallons) on a few occasions, just put it right in. Didnt dig it in initially, just sort of placed it in the tank, and some of it in the sump, waited a couple weeks, then i rearranged stuff and dug in some of the new rocks etc. Before you put it in, you might want to take the chance and examine it for aiptasia and the like. And if your sump is big enough, you might just want to toss it all in there for a few weeks. Best of luck! Lol, whenever I move any big rocks in the sand, I usually see some GIANT bristleworms......ever see that movie DUNE?
