White Fin Anpther Problem

[AnneSo]

Hello everybody!
I discovered this morning that a tiny part of the queue of my fish was white. Is that a sign of rotten fin?
I hope not and I don't know what to do..
Please help me!
I don't know the name of the fish..it's bigger than a guppy but still look similar. yellow/green with a red queue.
Thank you

 

[Miss Wiggle]

can you post a picture of it?

if not google image search for fin rot and white spot, see if any of the pics look similar

 

[AnneSo]

Alright,
I've been to the fish shop, and it was what I suspected it would be.
I changed the fish and they are going to cure him, apparently it's not too bad.
I checked the water and it is fine!
Thanks

 

[Sibelius]

I don't know of many shops that replace fish when they fall ill, anyway, do make sure that there isn't an underlying problem, like perhaps water quality, as otherwise your new fish may contract the same disease, or condition.