Some copy pasta

Symptoms of fin rot
* The first signs of the disease are milky white areas appearing in the fish’s fins or tail, particularly around the edges.
* The fins develop a rather ragged appearance as the disease begins to eat the tissue.
* Eventually the disease eats all the clear fin membrane away, leaving just the fin rays.
* If the fin rot has affected the fish’s tail (also called tail rot), it may work its way through to the body of the fish.
* Secondary infections or diseases are common in advanced cases of fin rot, bringing new symptoms to the afflicted fish such as white cotton wool-like tufts or streaked patches of red.
Any of that ring true?
edit : browser issues today
Your LFS should have some medication for fin rot. It's generally caused by a combonation of stress and poor water quality. Are all your parameters in check?