Oxygen Deprivation of Goldfish

Symptoms of Oxygen Deprivation

In order to thrive, a goldfish requires a good amount of dissolved oxygen in its tank water. When oxygen levels in a goldfish tank are low, goldfish can suffer from oxygen deprivation, leading to the death of the goldfish. The most noticeable symptom of oxygen deprivation is a goldfish that gasps for air near the surface of the water. That being said, goldfish with certain goldfish parasites or suffering from other poor water quality issues like a pH crash include gasping as a symptom. By testing for dissolved oxygen, oxygen deprivation can be diagnosed or excluded as the cause for this symptom.

Increasing Oxygen in Aquarium Water

Cold water contains more oxygen than warm water and thus cooling the goldfish tank water is the first step to increasing dissolved oxygen in the water. In an aquarium, the heater should be turned down to under 70*F and the tank should moved out of any direct sunlight. In a outdoor goldfish pond during summer months this can a difficult task. Aside from adding temporary plants next to the pond or floating aquatic plants in it to add shade, or even placing frozen water filled milk cartons, there little to be done to drop the temperature.


Floating plants might provide shade and lower the water temperature which will increase dissolved oxygen in the water but the fact of the matter is, by adding aquatic plants during this time will actually lower the dissolved oxygen for two reasons. The first is that aquatic plants take in oxygen at night and will compete the goldfish for oxygen. This is the main reason for any fish loss over night during warm periods. The other reason is that floating aquatic plants lower the surface area of the water surface lowering the amount of oxygen that can mix with the water.


Instead of adding more aquatic plants, run all fountains and waterfalls overnight 24/7 to keep higher levels of dissolved oxygen in the goldfish pond water and run air pumps and airstones in goldfish aquariums 24/7. Keep lower stocks of goldfish and feed them less. For up to a few hours after feeding, a goldfish’s demand for dissolved oxygen can be double. In an emergency, where goldfish are suffering from oxygen deprivation, add hydrogen peroxide. Use a spray bottle that contains a .03% USP solution and direct the spray down into the water; no more than one squirt for every gallon of water. An overdose can burn the skin of the goldfish.




photo credits: Bensonkua