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Identifying and Treating Common Diseases in Saltwater Aquariums

How to Keep Your Fish Free of Disease

Once you’ve set up your aquarium and have a collection of beautiful fish happily living inside it, the last thing you want is for your fish to become ill or die. Fish that are kept as stress-free as possible in a clean and well-maintained tank are less likely to succumb to disease. Nevertheless, no matter how hard you try to avoid it, fish get sick from time to time just like other animals and people. The best thing you can do is to be aware of the most common saltwater fish diseases and to know how to treat them.

Saltwater Ich

Known also as “white spot disease” and “marine ich,” this is one of the most common diseases to infect saltwater fish in aquariums. The disease is caused by a parasite, and the most obvious sign of it is small white spots or patches that begin to appear on the fish’s fins, gills, or skin. The affected fish may also have cloudy eyes, excess mucus, and ragged fins as well as a thin and pale appearance.

Treatment: Treat with copper. Be mindful that copper can be dangerous to coral so if you have coral in the tank, quarantine the infected fish before treatment.

Saltwater fish tank with one clownfish looking directly at the viewer

Marine Velvet

Marine velvet is also a common disease and spreads quickly when left untreated. Fish afflicted by the disease will have inflamed and bleeding gills and their lung tissue will begin to deteriorate. The infection will also become noticeable on the body where dull, velvet-like white spots will begin to appear. In addition, the fish may start behaving oddly and stop eating while gasping and scratch against objects. Clownfish, tangs, and angelfish are particularly prone to this disease.

Treatment: This disease has a high mortality rate but can also be treated with copper.

Fin Rot

Fin rot is a bacterial infection that often begins with poor water conditions and fish nipping at each other. The main symptom is fraying fins that look ragged. The fin could become so infected that it could be destroyed entirely. The infection could also spread to the skin and into the gills.

Treatment: Quarantine the infected fish and treat them with anti-bacterial medication while doing a partial water change and ensuring the proper function and maintenance of the filter.

Wasting Disease

This disease is also known as fish tuberculosis. It is not always easy to treat and can be challenging to diagnose. The fish will eventually start developing skin lesions and their eyes will look like they are popping out. They will stop eating, become lethargic, and their scales may begin to drop off. Unfortunately, by the time these symptoms appear, it may be too late to save the fish.

Treatment: Although unlikely, it is possible for fish to recover from this disease with antibiotics. However, the best way to treat this disease is to prevent it altogether. The bacteria that causes it is transmitted through raw fish and feces. Try not to feed your fish raw fish and keep the tank clean and feces-free. If your aquarium becomes infected, it is also recommended that the water be replaced and that the tank be sterilized before bringing in new fish.

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