Why is my goldfish eating bubbles constantly?
This behavior sounds like “piping”, and is a sign of oxygen deprivation. Do 25% water changes every day for a week and see if the behavior stops (remember to dechlorinate any water you put into the tank). If it does, then you know it is a problem with oxygen or water chemistry. How big is the fish and how big is his tank? If the fish are too big for your aquarium, then Oxygen will be a problem. Filtration will not add very much oxygen…at best it will agitate the surface of the water. This agitation is what is adding oxygen (via gas exchange at the surface), not the filter itself. All the filter is doing is removing particles in the water. Air stones do not add oxygen either (which is a common misconception…the bubbles from the air stone do not dissolve in the water or anything)…but they do agitate the water at the surface, which encourages gas exchange also. And do so much better than your filter actually. Filters are beneficial, but not for adding oxygen. Live plants will help a
