Saltwater Tropical Fish Disease

Fish Care

The main factors that produce Saltwater Tropical Fish Disease in a tank are:

• Introduction of disease from new fish.  Placing new fish in a quarantine tank for observation and introducing as little water as possible from the new fish bag can help with this problem.  Also review the information on Buying Saltwater Tropical Fish.  Quarantining is also a good idea as soon as indications of disease are apparent in the tank.

• Stress can cause fish to become ill.  Factors promoting this are the result of transportation as well as improper pH, temperature, salinity, oxygen and ammonia levels

Common Diseases and Treatments

• Saltwater ich (Cryptocaryon Irritans) is a common bacterial disease which covers the fish in tiny white spots.  Copper sulphate (AquariSol and Coppersafe), formaldahyde (Quick Cure) and malachite green (Quick Cure) are standard remedies.  These are added to the tank, as ich goes through a life cycle and will remain in the substrate unless treated over several days.  See comments below on the use of Copper and then review our information on freshwater ich for more details on treating a Fish Only saltwater tank.

• Velvet (Oodinium or Amyloodinium ocellatum) is similar to Cryptocaryon Irritans.  The fish develops very small off-white or yellowish spots.  The treatment is the same as for Saltwater Ich (Cryptocaryon Irritans).

• Clownfish disease (Brooklynella Hostilis) is a slime covering the body and can be treated with formalin or malachite green in a quarantine tank for several days.  It affects other species, but is most frequently found to affect clownfish. 

• Film on the eyes is a bacterial disease.  Treat the fish in a quarantine tank with a penicillin based drug such kanamycin sulfate or gentamycin sulfate.

• Dropsy is a bacterial infection where the fish becomes bloated.  Treat the fish in a quarantine tank with a penicillin based drug such as sulfa, gentamycin sulfate or tetracycline.

• Head and Lateral Line Erosion is a condition caused by poor diet.  The scales deteriorate along the head and flanks through a series of lessions.

Copper is continually debated as a treatment in fish tanks.  Copper definitely cannot be used in Reef Tanks or with invertebrates.  It is excellent at killing infections though and may be used in a Fish Only tank.  Remember to remove chemical filtration such as carbon filters, during the treatment.   Improper dosage can easily kill the fish and contaminate the tank.  Copper is absorbed by plants and then released when they die.

UV Sterilizers are ultraviolet lights that effectively kill bacteria floating in your tank.  Unfortunately, UV lighting is also hard on your fish.