So far all my platy fry except one boy has died. I think it was due to a mini cycle in my tank after my cartridge broke unexpectedly and I just stuffed some AquaClear foam in there instead. I had hoped I had enough BB throughout the tank that that wouldn't happen. It's also possible that Rembrandt chased them to death lol.
He was the only Betta with long fins that I have so he had to go in there because Mercury was literally chasing them to death whereas Remmy couldn't care less after he found they were too quick for him. So only one surviving at the moment, it's a Sunset Wag fry, still only about 2 months old and was the second runt. So he's still kind of small but his colors are finally coming in a little better!!