Over time, gunk and grime build up on water pumps and it can have many detrimental effects. For example, as the impeller becomes grimy, the pump could lose some significant flow speed. Alternatively, the water flow may not be impacted, but the pump will have to work harder to create those same rates, which could cause higher electricity usage and a shortening of the pump’s life. Or, in the worst case scenario, the pump could experience both issues, slower flow rates and having to work much harder. For these reasons, it is crucial to break down the pumps every so often for a good cleaning. Just take the pump offline, soak it and its components in vinegar, give them a good scrubbing, rinse thoroughly, and put it back into service. If you are a diligent aquarist, you might even have a backup on hand to just swap them out so you experience minimal down time.