Worms in Fish Tank Gravel

Planaria worms are the result of excessive organic particles in the water. They appear as thin, wriggling white worms crawling around in your tank's gravel and clinging to the walls. The worms are not parasitic, but their presence can still be a detriment to your fish if not treated properly.

  1. About Planaria

    • Planaria worms are flatworms of the Platyhelminthes phylum that are found exclusively in freshwater environments. They are stringy and dull white with small eye spots and a mouth, reaching lengths no more than 2 or 3 inches. They are bottom dwellers that spend most of their time in the tank's gravel feasting on organic particles.

    Dangers

    • The worms are not parasitic and pose no direct threat to your fish. They eat organic particles like uneaten fish food in the gravel, meaning that their presence is an indicator of overfeeding and possible ammonia spikes from all of that uneaten food. They do eat fish eggs, making them undesirable in tanks where fish are purposely bred.

    How They Spread

    • The worms are easily spread between aquariums. They reproduce using cocoons containing several embryonic worms that stick to various surfaces like rocks, plants or even fish. Planaria can be accidentally introduced into your aquarium by adding a plant, piece of decor or a new fish carrying the cocoon. The cocoon will release the baby worms into the new environment. Planaria can also reproduce asexually and will occasionally split into clones.

    Treatment

    • The worms can be eliminated by cleaning the gravel thoroughly and gradually over several days. Clean the gravel using a gravel vacuum, which is a siphoned hose that can suck up water and particles without sucking up the gravel. Apply the end of the vacuum to the gravel to suck up worms. Replace the lost water with fresh, dechlorinated water when you have drained a quarter of the aquarium. Repeat these steps for several days until the infestation has diminished. Add QuickCure to the water, a copper-based treatment, for a more thorough treatment.