X-shooter spectra covering iron (left) and calcium (right) lines in four cool, hydrogen-rich white dwarfs from the NLTT catalogue. Photospheric calcium lines are observed in three stars, while iron was only observed in NLTT 1675 and 6390. In contrast to our initial report (Kawka et al. 2011), our new X-shooter spectra show that NLTT 23966 is devoid of calcium. The possible identification of aluminium is reported for NLTT 1675.