Symptoms:

• Fins look shorter and shorter, like they are dissolving or shredded
• There may be a dark, red or white edge to the fins
• Base of fins may be inflamed
• Fins may be clamped
• Fish may have stopped eating
• Loss of color

What is it?

Fin rot is caused by one or more of several gram negative organisms. Aeromonas, Pseudomonas, or Vibrio are the most common.

How did it get there?

This disease is very common and caused by stressed fish. The most common cause of stress in fish is poor water quality. Poor water quality might result from overcrowding of an aquarium (rule of thumb says 1 gallon of water per inch of fish), old fish food, or overfeeding. A fish may also be stressed from being handled. Low temperatures for fish with long flowing fins is a common cause of stress as well as an incorrect pH for the fish. PH tests are available at your local pet store.

Treatment

If your fish has fin rot from poor water quality, the first thing you should do is a water change. Do not do a full water change as it will only stress your fish more. Treatment with an antibacterial medication that works for gram negative bacterium such as Tetracycline or Maracyn are good choices. Follow the directions that come with the medications. Addition of 1 tablespoon of aquarium salt per every 10 US gallons will also help your fish reduce stress.

Prevention

• Since this disease stems from poor water quality, vacuuming out all uneaten food and feces will help keep your water clean. Also dating your fish food will help prevent accidental feeding of old food. Keeping the proper water conditions for the fish that you own will help reduce their stress and increase their immune systems. Do no overcrowd your tank and watch for fights between your fish as their fin tearing might be a result from a fin nipper.