Fin Rot Overnight?

[Spiceweasel69]

Took some pics of firemouth 2 days ago and posted to see if i can sex them. Looked at them today and all thier fins appear stringy and tatty. They were okay yesterday, and definateley great the day before.
They have gone whitish and bits of fine are pale white so i guess it fin rot for sure.

All other fish are in perfect health. I keep angels and i scrutinised them, and they are absoluteley perfect - not a single fin on any other fish is anything other than 100% healthy. The firemouths chase and nip each other a little - i dont know thier sex but hope to soon.

Can fin rot work this fast. Whats my best treatment. I put anti fungus and fin rot in - how llong do i use it for? is there anything else i can do? Is this normal for spawning fish?

 

[tttnjfttt]

Fin rot usually shows up as the fins eroding, rather than than having the fins shreded. Is there any chance the firemouths could have been fighting? It sounds like it may have been from agression.