  X-ray missions with microcalorimeter technology will resolve spectral
features with unprecedented detail. In this work, we improve the H-like
K$\alpha$ energies for elements between 6 $\leq Z \leq$ 30 for the release
version of the spectral simulation code Cloudy to match laboratory energies. We
update the ionization potential ($I_{\rm ion}$) for these elements and add a
fourth-order polynomial to the level energy difference. This brings the release
version of Cloudy into a near-perfect agreement with NIST. The updated energies
are $\sim$ 15-4000 times more precise than that of the current release version
of Cloudy (C17.02). These new changes will be a part of the next update to the
release version, C17.03.
