Bacteria/Fungus

[JaredL]

I have some fairly new coryadoras exhibiting what appears to be white buildup around fins. The LFS had them in tank w tetras, and I think they were fin nipping. I first quarantined w med trio for a week before adding to community tank. Unfortunately, I don't use a glass QT tank so didn't notice the problem until I dropped them into community tank. So after a couple weeks it hasn't gone away, and I have moved them back to a glass QT tank. My questions are:

Am I correct in my diagnosis? 

If I am right, should I use Maracyn or aquarium salt? (Have never used salt, but I own it for hatching bbs)

Parameters: 8ph,0 ammonia and nitrites, 10ppm nitrates, high gh and kh.

[Roko]

It looks like fin rot to me best cure for that is clean water and good water quality and fins will grow back. If it is white cotton like stuff growing on damaged fins it's possibly secondary infection that i would treat with antibiotics. But first make sure it's not just regular fin rot. As salt goes if you don't have experience using it with corys i wouldn't use it they are sometimes sensitive to it.

 

[Roko]

And just wanted to say i am not expert in treating fish for diseases so make your research especially on corys and fin rot and make your decision based on it.

[JaredL]

@Roko thanks for the advice! Do you have an idea how long it should take for mild fin rot to clear on it's own? They were in my community tank, which is a clean tank, for at least a couple weeks with no sign of improvement. Understanding you aren't an expert, but possibly more experienced: would you recommend putting back in community tank and waiting longer? Or since I already have them in QT just treat with antibiotic? Thanks

[Roko]

@JaredL if your quarantine is cycled i would leave them in it if nothing so you can see them clearly and react if necessary. Just do more frequent water changes. If you decide to put medicine you could go with one more trio treatment but then don't do more water changes then necessary.

 

If it's just fin rot and you are treating with clean water approach it can take few weeks until fish is  recovered but definitely you should see improvement.

Also feed cory with good quality food.