A built-in overflow is the most efficient method of draining aquarium water to a filter. If your aquarium does not have built-in overflow, CPR Continuous Siphon Overflows/Prefilters are the best means for getting water from an aquarium to a filter system without expensive modifications to the tank. They quietly skim up to six times more water than units with tubes.
The advantages of CPR Continuous Siphon Overflows/Prefilters include:
* Adjustable water level allows you to
easily change the level in your tank.
* Black top reduces algae growth.
* Plastic screen to prevent fish loss.
* Quiet operation.
