The platinums are pretty slow growing as well but tonight I saw the first signs of the fish maturing, they started tail slapping and lip locking. Currently just setting up dominance but a good sign that they are healthy and progressing. I've also noticed they are more finique eaters than the golds or the wilds. Those types go after everything in the tank where the platinums will take flake food unenthusiasticly but when frozen brine shrimp or mysis shrimp are dropped in the tank they can't get enough.