Hi all - I'm kinda panicing here - About 3 or 4 weeks ago, I got 4 new Bettas from the LFS, and until two days ago they were all in their own tank with no apparent problems.
A couple of days ago, I finally got my 50 gallon divided into 4, and gave all 4 a new 12 gallon home in the tank.
This morning, I got up to discover that one of them, a brilliant blue VT (I think) had a bad case of fin rot (About half of each fin looks black and frayed). On top of that, while his snout was dark before, now it looks white and mottled. He's still very lively, but given the change in location, it's hard to make a judgement about his behaviour.
I've already moved him back to his 2.5 gallon temp tank, and am about to add aquarium salt to it, which I will combine with daily changes to his water until I see some noticable improvement.
What's got me panicked - The other three aren't showing any sign of rot, but I'm worrying what to do about them - Do I start adding salt preventatively? Or should I just wait and see if they develop problems?