Guppy is Swimming at Top of the Tank

If your guppy is constantly swimming at the top of the tank, swimming upside down or swimming in small circles, it is likely due to a problem known as swim bladder disorder. In other cases, though, your guppy may be fighting to obtain oxygen. If you've exhausted all other remedies to care for your fish, consult an expert to help rectify the problem.

  1. Swim Bladder Disorder

    • The swim bladder is an organ used by fish to keep their balance while underwater. If the swim bladder is deformed or diseased, the guppy is unable to stay balanced, causing it to sink to the bottom, rise to the surface, float upside down or spin in one place. One symptom to keep an eye out for is a lack of appetite. Guppies are not particularly prone to swim bladder problems, according to Guppy Place.

    High Nitrate Levels

    • A high concentration of nitrate in the fish tank can cause symptoms that mimic swim bladder disorder in guppies. Test your tank on a regular basis to make sure the symptoms your fish is exhibiting aren't from nitrate poisoning.

    Lack of Filtration

    • If your fish tank has no filtration system or water-movement system, a lack of oxygen may be the cause. Your guppy could be surfacing to gain access to better water. If you think your fish is straining for oxygen-rich water, install a proper filtration system and clean the tank.

    Tall Plants

    • If your guppy is consistently swimming at the top of the tank near tall plants, this behavior is normal. Guppies enjoy darting in and out of hiding places such as weeds. If you're afraid that the guppy's behavior could be harmful -- for example, if the guppy is at risk of jumping out of the tank -- remove the plants or exchange them for shorter ones.