Crushed coral question…

OK I’m sold on the idea that I need to get this stuff. Do I want the Caribsea Arag-Alive Florida Crushed Coral or the Florida Crushed Coral #15? Can I put this stuff in a fresh-water tank? (I’m leaning toward changing over to brackish but for now it’s fresh). Will my filter be OK with this stuff? It’s a RENA XP3 filter. Thanks to Michaela and Scott for answering my behavior question. Michaela, can you help me figure out the sex of my WCT? It is just over 4″ and like I said its plastron is definately concave, I’m not sure about the tail but it seems like a bulkier turtle rather than a streamlined one. Thanks so much! Kathleen