I've heard from my sister that bringing a crowntail into direct sunlight fora few minutes every so often will help keep their branches strong. and that sometimes it darkens the betta's color.
So as a quick little question: Is this completely true?
I've been bringing Ratchet out a few times and he doesn't seem to mind the sunlight at all, and it's a good time for me to see his light blue coloring. Recently, after the last time I brought him out for a few minutes, his fin edges began to darken a little bit. They're almost black now when they used to be the same light blue/gray of the rest of the fins. I'm ruling out fin rot since his fins are only growing longer and the fact that he has clean water and a healthy diet. He's only torn once and that was from excessive flaring at another cupped betta. The discoloration is mainly on his anal fin, which has always been a reddish color.
I'm not worried about it or upset, just curious. Are there any other tricks to keeps his fins healthy and strong (I don't want them to end up droopy like Yorick's)?