Why Is My Goldfish Eating Gravel?

Although goldfish are easy to care for and an ideal pet for young children, they can exhibit behavior that may make the owner think something is wrong. Some goldfish owners become concerned when their fish appear to be eating the gravel lining the bottom of the tank.

  1. Food

    • Along with fish food, goldfish also like to eat algae and lichen growing on stones and rocks. Aquarium gravel can contain air pockets where this marine plant life can grow. If a goldfish appears to be eating gravel, it may be sucking the algae off the stones and spitting out the small gravel.

    Mating

    • Goldfish, like other wild animals, tend to act differently when it is time to mate. Goldfish perform a ritual called nipping where they grab at things on the surface or on the bottom of the aquarium. This can include small pieces of gravel. Both males and females may indulge in this behavior.

    Decoration

    • Fish like to tend to their environment, tidying up in the same way a human would dust and vacuum. This can involve moving stones and pebbles around by collecting them in their mouths and spitting them out somewhere else.

    Solutions

    • Some goldfish enthusiasts recommend using only large gravel or another substrate in goldfish tanks to eliminate any danger of choking. Owners should select gravel large enough to prevent the goldfish from fitting it in their mouths. The size of the gravel may need to be increased as the goldfish grow.