I really wanted to like this - unfortunately, it's not functional. The "filter" is a tiny rectangular piece of carbon mesh around the small motor. It claims to keep the water clean for a week, but after the first week of using it, THE WATER WAS SO CONTAMINATED. This made me extremely nervous, bc my cat has had clostridium perfringens before and I was worried this would cause it to come back. I spent over $300 at the vet to get a diagnostic done. Also, it was clearly not designed with user experience in mind. You have to put a plastic tube (attached to the motor, which is suction cupped onto the bottom of the fountain and doesn't even stick properly there) into the cactus part and you can't see where to fit it in and you're just fumbling around. If you accidentally turn the motor on (no indication of which way the switch needs to be to be 'on' so you can't tell if it's not working because there's not enough water of if it's just off) while there's water in the fountain and you're still trying to put the tube in, water will spray everywhere onto your floor. If you put the tube in first and then pour water in, you have to put your whole hand in the water and somehow get your fingers between the carbon filter and the motor to turn on the motor. Unfortunately when I bought this, H&P's return policy was that you just couldn't return any used items, so it's just useless and I have to buy a different water fountain. It's really cute but just so unusable and defeats the purpose of having a filtered water fountain in so many ways.