Attach the plastic tubing to the filter ports, making sure that the water will flow in the right direction.
Seal the tubing holes in the sink cabinet and floor under (behind) the aquarium with caulking.
Turn the water on at the saddle valve and check the entire system for leaks. Check the water level in the tank or sump and adjust the float valve as required, making sure that the valve closes completely at the appropriate water level.
There you are!! You now have an Auto Top Off system installed on your aquarium.
The photo above is a down-the-side-of-the-sump view of the float valve installed in a sump.
