Neon Tetras Have White Areas On Tail/fins. Is It Fin Rot? :(

I have 4 neon tetras (out of 10) that have developed white areas on wither their tail or fins and the fins seem to be wasting. It's not whispy yet but I wondered whether this might be fin rot or could it be some bacterial problem. I have transferred them into  quaranteen tank but have not treated them with anything yet. Can anyone recommend anything please?

Thanks Sue 

I usually wait until I see new growth on the affected fin/tail. And I often have to treat for longer than 3 days.

Lumps on the body is one of the symptoms of NTD unfortunately. But swimming oddly and losing colour are other symptoms which your fish don't have. I'd keep them in quarantine till you're sure one wayor the other.

NTD is infectious but only to other neons. There is some debate as to whether other members of the Paracheirodon genus (cardinals, green neons) can get it, but I think they are the only likely ones. (Don't quote me on that, I'm not very good with diseases. It's possible some species of other tetras might get it, but nothing else)

I have found that with some fish it takes a lot longer than the med says, sometimes as long as 2 weeks. I'd treat a bit longer just in case, but if it is actually NTD, nothing will help I'm afraid.