To check for leaks from the Nivito faucet base, use a cup or paper towel and place it under the spout. If water is dripping from the faucet, you may have a faulty cartridge. To test for a leak, you can spray some vinegar on the water in the container. If you can't see the leak, then it's likely a water leak. To clean the faucet, place it upside-down and press the retaining nut firmly against the stainless steel ball.