Why Fish Are Dying in an Aquarium

Fish are fragile animals that are very sensitive to a number of environmental factors. In an aquarium, the water must be clean, properly filtrated, heated and dechlorinated, but even then, fish have a tendency to die off mysteriously. There are actually numerous reasons that fish may be dying in a home aquarium, many of which can be very easily remedied.

  1. Dechlorination

    • Tap water often contains chlorine and other chemicals harmful to fish.

      Many people fill their tanks with water straight from their taps. Tap water often contains chlorine, along with other chemicals, that can be highly toxic to fish. All tap water must be properly dechlorinated when it is added to an aquarium. Dechlorinating water is as simple as adding a chemical like Tap Water Conditioner or Prime to the water as it's added; these products will eliminate any traces of chlorine and many other harmful chemicals.

    Heat

    • Fish like this African Cichlid require temperatures in the mid-80s.

      Fish are exothermic animals, meaning that their body temperature is directly affected by the water temperature. Most fish are tropical, meaning that they need water temperatures around 80 degrees Fahrenheit. Keeping this temperature can be achieved with a simple water heater that typically rests along the wall of your tank's interior. Some fish, like goldfish, are capable of withstanding colder temperatures, but many absolutely require a heater for survival.

    Filtration

    • A tank can become cloudy without a proper filter.

      Proper filtration is one of the most important factors when maintaining any aquarium. A proper-size filter not only keeps the water clean and clear, but it removes harmful chemicals, provides a growing area to promote the growth of beneficial bacteria and oxygenates the water. Without a filter constantly cycling water, the aquarium water's oxygen level will rapidly deplete, suffocating your fish.

    Ammonia

    • Overcrowding in an aquarium can lead to spikes in the ammonia level.

      Ammonia is a very common killer of fish. Ammonia is released when freshwater fish urinate and is removed with the filter, which typically contains carbon that absorbs it. Ammonia spikes can also be caused by the death of a fish; if the dead fish is not removed from the tank immediately, it will release deadly ammonia into the water during its decomposition. Ammonia can also be added by overfeeding; giving a fish more food than it can handle will result in leftover food's sinking to the bottom and decomposing into ammonia. Overcrowding an aquarium with more fish than it should accommodate also contributes to excess ammonia.

    Ich

    • Ich is a very common condition in aquariums that can be fatal if not treated. Ich is a parasite that takes the form of white spots sprinkled over a fish's body. These parasites embed themselves into the fish's skin during their life cycles, before finally erupting from the boils, possibly killing the fish. Ich most commonly results from sudden fluctuations in temperature, and can be prevented by keeping the temperature as constant as possible. It can be treated by warming the water or providing a copper solution.