Using this Drinkwell pet fountain is easy. First, fill the 1 - gallon reservoir with clean water. Then, place the charcoal filter in its designated spot. Plug in the fountain, and watch as the free - falling water stream starts. Your pet can now enjoy fresh, filtered water. Remember to change the charcoal filter regularly to keep the water tasting great. Also, clean the 5 - inch deep bowl and the reservoir every week to prevent the growth of bacteria. When refilling, use fresh water to ensure your pet always gets the best. If you notice any issues with the pump or the water flow, unplug the fountain and check for blockages.