dry coral

Hello, I was told not to use dry coral as dry rock. I got these that came on a deal with other rocks. If dry coral is the same as aragonite wich is calcium carbonate, is there a real reason not to use it?. The goal is to set up a reef, anyone has experience with using dry coral on a reef?

Had this tank setup going on 7 years,great set up with the refugium in the basement makes it so much easier to maintain.but if you dont have a basement i have the sump that goes under the tank to.if your interested send me an email and we'll talk.:)

guys so a friend of mine gave me a big chunk of dried coral he basically took of out of his clients tanks dries them outside and sell thems i guess. So i got this chunk from him it’s alottle dirty from like outside debris is it okay to rinse it with tank water and re enter it into the tank? Or...