Can I put these in my QT. I have a couple plastic items in already. I want to break up current trying to keep well aerated. Treating with coppersafe from Fritz. I think the fish need a place to chill out of current. Unless the Clown is enjoying his ride. IDK.
Those look like some other kind of rocks than the typical calcium carbonate based live rock used in saltwater aquariums. I'd caution using those in case any harmful minerals start to leach out into the water.