Fin rot is most likely not going to occur in well kept aquariums. Fin
rot is caused by an excess amount of bacteria in the aquarium that
should have normally been taken care of with weekly water changes.
Symptoms are violent on the fish, including blood streaked and ragged
fins and will eventually eat away the whole fin of the sick fish.
Treatment can be found most local pet stores.
Occurrence: High. Deadly? Yes. Contagious? Yes. Treatment Available? Yes. Fish Assist Problem Code: 4 (Serious/Moderate)
Fins look shredded
Fins decreasing in length
Loss of color in fins
Fish tends to dart around aquarium
Isolation from school (If applicable)
Do a water change and continue doing them frequently (twice a week).
Many fish stores offer treatment for this disease at a cheap cost of around $8 CAD. When treating the aquarium (the whole aquarium must be treated as this disease is highly contagious) make sure to follow the manufactures directions.
As always, maintain good water quality
Feed the fish in smaller quantities as to not allow fish food to accumulate in the aquarium