Goldfish may die easily due to weak genetics or improper living conditions.
With that said, when bought from reputable breeders and taken care of properly, goldfish are actually one of the hardiest fish species you can get. Most species of goldfish can typically live for 10 to 15 years, with some varieties even reaching up to 30 years.
Unfortunately, due to their status as disposable pets, most people don’t give their goldfish proper care, causing them to die prematurely.
If your goldfish keep dying easily, one or more of the following problems may be the reason.
Unsuitable Living Environment
If your goldfish passed away soon after you brought it home, the reason might be its living conditions. Although the image of a goldfish in a small fishbowl is familiar, such a small environment is unhealthy for these fish.
Small tanks don’t give goldfish enough room to stay active, and the water quickly becomes contaminated with ammonia and bacteria.
Goldfish need to live in tanks with plenty of clean water, a richly decorated environment, and a temperature that is comfortable for their individual species. A 20-gallon tank should be enough space for one goldfish.
Poor Water Quality
Not all types of water are suitable for goldfish. These freshwater fish can’t survive in saltwater. Fresh tap water isn’t suitable for these fish either, because tap water can contain chlorine and heavy metals which will kill goldfish.
Make sure the water in your tank has been dechlorinated. Additionally, clean the tank at least once a week to prevent buildup of nitrates, bacteria, and ammonia, which can also kill a goldfish.
When a goldfish is overfed, it will eventually stop eating the food that is added to the tank. This leftover food sinks to the bottom of the tank and starts to rot, which in turn produces ammonia. Ammonia is poisonous to goldfish and can kill them if the tank isn’t cleaned out enough.
If you see any food at the bottom of the aquarium, remove it immediately, and reduce the amount of food given to the goldfish.
Adult goldfish only need to be fed two to three times per day. They should only receive an amount of food that’s about as big as one of their eyes. If they don’t finish all the food in two minutes, remove it from the tank with a siphon or a net.
Parasites or Bacterial Infections
Infections caused by parasites such as ich are common in aquariums, but they can kill a goldfish if left untreated.
The most common parasite that affects goldfish is ich. A goldfish that has ich will look like it’s been sprinkled with salt. Medicine that treats the water in the entire tank is the best treatment for ich.
Other parasites may cause different symptoms. Look for new red patches, bruising, red or swollen gills, torn fins, slow or tired behavior, and missing scales. Every parasitic infection will cause different signs of illness, so if you’re not sure how to diagnose your goldfish, contact an aquatic veterinarian.
Bacterial infections are also common in goldfish tanks. Symptoms of a bacterial infection include cloudy eyes, a white film on the goldfish’s body, bloody patches, sores or new bumps around the eyes and mouth, and tattered, shaggy-looking fins.
Treating bacterial infections can be difficult, and diagnosing them is even harder. If you think your goldfish has a bacterial infection, contact a fishkeeping professional or aquatic vet for help.
Accidents or Injuries
Goldfish can injure themselves by accidentally bumping into things in the tank. They might tear their fins or tail against sharp rocks, or burn themselves near the heater.
Make your tank safer by removing sharp objects and placing a guard over filters and heaters. Cover the tank with a well-fitted lid, and eliminate small gaps in the tank where a goldfish could get stuck.
Fighting With Tank Mates
If a goldfish is fighting with the other fish in the tank, it could get injured or die. Keep your fish in a large tank with plenty of space, and make sure to choose compatible tank mates for your goldfish that are both peaceful and of a similar size.