Any article you read on keeping an aquarium will emphasize the necessity of maintaining a clean tank. This is because the most common killers of fish come partially from an unclean tank and sneak up on your fish silently. Regular maintenance of your aquarium will help prevent the three major killers of freshwater aquarium fish from making an appearance.
The number one killer is ammonia poisoning. Ammonia poisoning occurs when ammonia levels in the water rise. This usually happens when you set up a new tank, or when a mechanical filter fails, or when colonies of good bacteria die due to fish medications or changes in the water chemistry. The symptoms of ammonia poisoning on your fish are: purple or red gills, fish go to the surface gasping for air, lethargy, loss of appetite, fish lying at the bottom of the tank, and red streaks on their fins or body. To treat for this disease, bring the water’s pH balance to 7.0 or lower, change 25-50% of the water, discontinue or reduce feeding so less waste is created and use chemicals to neutralize ammonia. There are steps for prevention you can take to make sure this never happens again. Stock a new tank slowly and do not introduce too many new fish at once. Test the water regularly, especially when adding new fish, medicate sick fish and repair your filter quickly when failure occurs. You can probably guess the final prevention advice -remove uneaten food and change water regularly!
After ammonia levels elevate, nitrate levels follow. This causes nitrate poisoning in your fish. Nitrate poisoning is also referred to as “brown blood disease.” A fish’s blood turns brown because of an increase in methemoglobin. The blood is then rendered unable to carry oxygen. Symptoms of nitrate poisoning are tan or brown gills, rapid gill movement, listlessness, and again you will see fish near the water’s surface gasping for air. To treat your fish for nitrate poisoning, do a large water change (75-100%), Add salt (preferably chlorine salt), reduce feeding, and increase aeration. The salt idea sounds strange for a freshwater aquarium, but surprisingly salt prevents methemoglobin from building up. As always, there are cautionary steps you can take to prevent nitrate poisoning from occurring. The preventative actions you should take for nitrate poisoning are actually the same as they are for ammonia poisoning. Clean your tank, clean your tank, clean you tank!
Finally, the most common killer or freshwater aquarium fish is algae. Algae is the greenish fog that appears in the aquarium’s water. Algae grow when an excess of nutrients is provided. Over growths of algae can occur when a light is left on, by overfeeding the fish, and not changing the water in the tank. To treat for overgrowth of algae, change 100% of the water and clean the tank. This can be prevented by feeding the fish sparingly, changing and cleaning the tank on a regular basis, getting snails or crabs that eat algae, and by having plants in your aquarium so they soak up nutrients.
The need to keep a clean fish tank can not be stressed enough. Keep your fish healthy and your aquarium pretty – the number one preventative measure for the major killers of your freshwater aquarium fish is to maintain a clean aquarium!