Fish disease and death can be very frustrating. Unfortunately, it even causes some people to give up on fish-keeping altogether. But a little knowledge along with some basic precautions can be very powerful in the health of our goldfish and koi. Maintaining good water quality is extremely important. It’s also important to make sure you are starting with healthy fish. If you purchase sick fish, it’s going to be an uphill battle at best. Buy your fish from a dealer you trust. If you are keeping high-dollar fish then trust is not good enough. You should set up a quarantine pond for new fish before mixing them with your other fish.
If a health problem does arise, your first step should be to test the water (you do this once a week anyway, right?).
You may also be interested in our article on the Causes of Fish Stress.
| Symptoms | Possible Cause | Treatment |
| Cotton-like growths | Fungus | MinnFinn, Microbe-Lift BSDT, Sabbactisun |
| Open wounds | Bacterial Infection | MinnFinn, Sabbactisun |
| Gasping at surface | Oxygen deficiency | More aeration, fewer fish |
| Bulging eyes | Pop-eye, Bacterial Infection | MinnFinn, Sabbactisun |
| Swollen body and scales protruding from body | Dropsy, Bacterial Infection | MinnFinn, Sabbactisun (mainly for the other fishas usually it is too late for this fish) |
| Fins deteriorating | Finrot, bacterial infection | MinnFinn, Sabbactisun |
| Floats upside down, trouble swimming upright | Swimbladder disorder | Sinking food |
| “Flashing” through the water (sudden sidewaysbursts) or jumping | Parasite infectionWater toxin | Salt level to .3%*, Microbe-Lift BSDT, MinnFinn, ParazoryneWater Change |
| Colored fish turning white | Loss of pigment | More sunlight |
| Swollen gills | Flukes, parasite infection | Salt level to .3%*, Microbe-Lift BSDT, MinnFinn, Parazoryne |
| Lying on pond bottom | Flukes, parasite infection | Salt level to .3%*, Microbe-Lift BSDT, MinnFinn, Parazoryne |
| Scales raised (on only part of the body) | Parasite infection | Salt level to .3%*, Microbe-Lift BSDT, MinnFinn, Parazoryne |
| Strong red veins in the fins | Bacterial InfectionParasite InfectionAmmonia or Nitrite poisoning | MinnFinn, SabbactisunSalt level to .3%*Water Change, Ammonia Remover |
| White Spots (pinhole size only) | Ich, Parasite infection | Salt level to .3%*, Microbe-Lift BSDT, MinnFinn, Parazoryne |
*This level of salinity is not recommended with plants in the pond.