Call it a cistern. Call it a tank. Whichever way you slice it, it’s done a disappearing act. Heavyweight bathroom brand ROCA, in collaboration with Siamp, are launching a true innovation at ISH this March in the form of the Hydro In-Tank WC, which sees the cistern, along with all other functional elements, such as the flush buttons, fully integrated into the toilet bowl. The WC becomes a single, pleasingly sculptural, element that pays dividends when it comes to planning, installation and maintenance.