otto cats

Hi all, my Otto cat got this white cloudy things on its fins. Is that white cotton fin fungus or Columnaris ? What can I treat for that ?

I got a few ottos to help after the addition of spiderwood because I had a little algae bloom and the wood had some bacteria bloom (even though I boiled for 6 hours and soaked for 24). All is perfectly clean and beautiful and I wanted to make sure my Ottos had enough to eat so I got some algae...