Hi Jeff, Thank you for your inquiry. The Gaggia Unica uses the Mavea Intenza water filter. Here is a link to the water filter on our website: http://www.wholelattelove.com/Gaggia/mavea_intenza.cfm . Yes, you can use Dezcal descaler with this unit. Besides descaling every two to three months, you need rinse the brew group about once a week. If you do that, your machine should function properly.