  NaCaNi$_2$F$_7$ is an insulating, frustrated A$_2$B$_2$F$_7$ pyrochlore with
magnetic S = 1 Ni$^{2+}$ on the pyrochlore B site. Non-magnetic Na and Ca are
disordered on the A-site. Magnetic susceptibility measurements made on an
oriented single crystal, grown in a floating zone furnace, show isotropic
behavior at temperatures between 5 and 300 K, with an effective moment of 3.7
$\mu_B$/Ni. Despite displaying a large Curie-Weiss theta (-129 K),
spin-ordering-related features are not seen in the susceptibility or specific
heat until a spin glass transition at 3.6 K. This yields an empirical
frustration index of f = -${\theta}_{CW}$/T$_f$ $\approx$ 36. The spin glass
behavior is substantiated by a shift of the freezing temperature with frequency
in the AC susceptibility, bifurcation in the DC susceptibility, and by a broad
maximum in the magnetic specific heat. The observations as made on large single
crystals suggest that NaCaNi$_2$F$_7$ is likely a realization of a frustrated
spin 1 pyrochlore antiferromagnet with weak bond disorder.
