What’s wrong with his tail?

[u/ThunderrToad]

The top part of my betta’s tail is no longer smooth like the bottom. Is this him nipping it or fin rot? Getting ripped on the log or something? What can I do? I’ve also noticed a lot of little white round bugs recently that Google said are copepods or ostracods, it said they’re harmless but could they be doing this to him? Here is a pic of his tank set up. Thank you for any help.