Why Can't I Get My New Filter to Work in My Aquarium?

Aquarium fish continually release metabolic waste products into their water. These products create a toxic condition in the aquarium unless removed by a filter. Numerous types of filters exist, and the majority are powered by a motor. Canister filters typically require priming before they will function. In some cases, the impeller or impeller well may have been damaged during manufacture or in transit. Under most circumstances, you will be able to get your new canister filter to function if you pay attention to a few basic procedures.

  1. Impeller Well

    • The interior of the pump's impeller "well" may have warped during the manufacture. The aquarist can check for this by carefully feeling in the well with a finger. Deformities are unfortunately not repairable, and you will need to return the pump to the dealer or manufacturer. The motor may also be faulty, and aquarists can check that the magnet within the well is receiving magnetic current by removing the impeller and placing a screw driver into the well with the motor plugged in. Magnets that are receiving current will pull gently on the screwdriver from all directions.

    Impellers

    • The impeller must lock after it has turned 360 degrees. You will also need to return a faulty impeller to the store, as these cannot be repaired easily. Many canister motors are manufactured with ceramic shafts. This shaft can also break during assembly and cause the impeller not to spin.

    Priming

    • A number of canister filters require priming before they will start. Newer models have a priming button. Simply depress the priming button a number of times in order for the pump to start. If you are setting up a new canister that does not have a priming button, fill the canister with water and place the end of the return tube into a bucket, positioned below the level of the aquarium. Start a siphon effect by sucking on the end of the pipe and allowing the water to be drawn into the canister. Once water pours into the bucket via gravity, you can return the return pipe to the aquarium. Bad intake and return connections draw air into the system, which either produce streams of fine air bubbles in the aquarium or prevent the canister filter from starting.

    O-Rings

    • Canister filters that draw in air will not function correctly. Ensure that the O-rings are correctly seated. Lubricate the O-rings with a small amount of either silicone gel or petroleum jelly before putting them in place. These rings must lie flat in their grooves and must not be twisted in any way. Run your wet finger over the O-ring to ensure a good seal in the absence of petroleum jelly or silicone gel.