top fin

Hey, I've noticed the top fin of one of my platies has changed in the past week or so.It looks frayed/splayed out, almost as if you've taken a few threads from a woven material if you get what I mean! I have attached a pic of anyone could help me understand the change, thanks ☺️

I’ve had this filter on my new tank for about a month and it’s clogged twice. I have been told not to replace the filter yet because I haven’t gotten my tank established. So, I’ve been “swishing” it in water I removed from the tank at a cleaning. This last time the filter didn’t unclog and the...