Tested with water on one occasion. Otherwise never used.  Where you see a small white piece of plastic there was supposed to be a decorative gauge there but the company packed it poorly in shipment and it was broken off when it arrived.  If using I would suggest putting down some kind of drip mat because it does have a pretty substantial drip.  Capacity is 1.5 Liters (Approximately 50 fluid ounces or 2/5 of a gallon.)