Fin problems

Question
Hello Christy,

Recently I have purchased a Silver Arowana, which I named Noono, and it was probably the coolest fish I'd ever bought, but just the other night I noticed that its dorsal fin was not normal. It wasn't erect like some other Arowanas with full-standing dorsal fins. And The dorsal fin of Noono looks "choppy". I'm starting to think that it was because Noono is still young, and hasn't fully developed its features yet, but I'm not for sure. So if you could help Christy, I'd appreciate it deeply, and thanks in advance!

Answer
Hi Tom
If the fins looks tattered, torn, are disappearing, then I would consider that he may have fin/tail rot.  

First, check your water quality and make sure ammonia and nitrites are at 0 ppm, nitrates under 20 ppm.  If that's fine, then check if there's tank mates in with him-is anyone nipping it's fins, any fighting or bullying?

Usually when you see fin/tail rot, it's related to water quality though.  And, most of the time just making the water quality good is enough to let the fish heal on it's own.  If it's far along though, an antibiotic like Maracyn Two or tetracycline should be used in conjunction with taking care of the water quality.

As far as if it's still young and developing it's fins, I can't honestly say. I've never had an arowana, can't have that large of a tank in my house lol.  I would suggest checking that info with someone more familiar with that specific breed to see if that's the case.  But, "choppy" as a description makes me think of fin rot.  

Hope that helps and good luck!

Christy