High sako, I'm not sure if I can give you reasons for the split fins, but
being long fins there is much more chance of the fish in your tanks having
minor fights amongst them selves (and even just moving about the tank )
causing the fins to rip and tear- my L001 does it all the time - tearing fins on
wood just moving about , if it gets to be really bad I usually treat with "melafix"
to help heal the fins or wounds and "pimafix" to treat for infections.