1. Fill the intake chamber with water until it begins to overflow into the filter chamber, place the filter box cover on the power filter assembly. Turn the flow control knob to Maximum flow. 2. Fill your aquarium with water until the water level is 1 to 2 cm from the bottom of the runoff spillway. 3. Connect the power cord, only after ensuring that the safety precautions listed in "Important Safeguards" have been fully observed. Your power filter should begin operation within 30 seconds. If the power filter does not start, remove the filter box cover and slide the intake tube up and down. 4. Never allow the water overflow filter cartridge into the runoff spillway. If this happens, the filter cartridge is dirty and it should be replaced at once.