Once you have your tropical freshwater aquarium set up, cycled and the fish added you’ll need to keep an eye on them and look out for any signs of tropical fish diseases so that you can catch any problems before they get out of hand. One thing you should do is to to set up a quarantine tank for any newly purchased fish and only introduce them into your main aquarium once you are sure they are disease free.
What should you look out for and what are the symptoms of the common tropical fish diseases? This guide should help you spot some of the commonest problems that occur in tropical freshwater aquariums.
White spot – Ichthyophthirius multifilis or Ich is very common and characterised by small white spots on your fish. Ich is caused by a parasite and will be fatal unless quickly treated. You can treat the tank with a medication for this parasite but remove any charcoal filters if you have them. Also sterilise any filters, nets or artificial plants by placing in boiling water. Follow the instructions on the medication carefully, continuing for at least six days after you last see any spots on the fish. This is important to stop any future outbreaks. Make sure you monitor your fish closely after treatment as Ich has a nasty habit of returning.
Fin Rot – This is also caused by a parasite and tends to surface if the fish are stressed, perhaps because the water conditions are not ideal. It’s a good idea to place infected fish in a quarantine tank for treatment with a commercial preparation as the treatment can kill plants and nitrifying bacteria. A quarantine tank with clean water is also good for the fish if poor water quality has lead to the fish’s stress. If the disease is in it’s early stages you can treat by placing the fish in clean water, changing the water daily and adding aquarium salt at the rate of one teaspoon for each gallon of water. A week of this treatment should be enough and when you see new fin growth you can return the fish to your main tank.
Flukes – If you see your fish rubbing themselves in on rocks and objects or ‘flicking’ on the bottom they may have skin or gill flukes. These are parasites called trematodes and cause damage to the skin and lesions. They are hard to get rid of completely but you can use commercial preparations or salt baths daily for three or four days.
Velvet or Oodinium is another parasite that affects tropical freshwater aquarium fish. It is sometimes mistaken for Ich but velvet looks more like a fine dusting of powder rather than white spots. It is also more likely to occur if the fish are stressed by poor water conditions or a sudden decrease in temperature. It is fatal if not treated quickly but easier that Ich to cure. Use a commercial treatment and increase the water temperature to 82F. Salt baths can also help recovery.
Image by FJP

