Why is my fish coming to the surface?
The reason they are at the surface trying to breathe is due to a lack of dissolved oxygen in the water. The low levels of oxygen are mainly due to a lack of aeration or poor water quality, which can then cause the fish to stress.
How do I oxygenate my fish tank?
Increasing water movement is the quickest way to increase oxygen (O2) levels in a fish tank, as it allows more O2 to dissolve and carbon dioxide (CO2) to be released. This can be easily done using an air pump, performing large water changes, manually stirring the water, or placing a fan near the aquarium.
What are the signs of low oxygen in a fish tank?
Signs of Low Oxygen
They will swim less vigorously and even eat less often. As oxygen levels drop further, the fish will begin to show labored breathing and more rapid gill movements as they desperately attempt to get enough oxygen from the water by passing more water over their gills.