  The analysis of debris disk observations is often based on the assumption of
a dust phase composed of compact spherical grains consisting of astronomical
silicate. Instead, observations indicate the existence of water ice in debris
disks. We quantify the impact of water ice as a potential grain constituent in
debris disks on the disk parameter values estimated from photometric and
spatially resolved observations in the mid- and far-infrared. We simulated
photometric measurements and radial profiles of debris disks containing water
ice and analyzed them by applying a disk model purely consisting of
astronomical silicate. Subsequently, we quantified the deviations between the
derived and the true parameter values. As stars in central positions we discuss
a $\beta$ Pic sibling and main-sequence stars with spectral types ranging from
A0 to K5. To simulate observable quantities we employed selected observational
scenarios regarding the choice of wavelengths and instrument characteristics.
For the $\beta$ Pic stellar model and ice fractions $\geq 50\ \%$ the derived
inner disk radius is biased by ice sublimation toward higher values. However,
the derived slope of the radial density profile is mostly unaffected. Along
with an increasing ice fraction, the slope of the grain size distribution is
overestimated by up to a median factor of $\sim 1.2$ for an ice fraction of
$90\ \%$ while the total disk mass is underestimated by a factor of $\sim 0.4$.
The reliability of the derived minimum grain size strongly depends on the
spectral type of the central star. For an A0-type star the minimum grain size
can be underestimated by a factor of $\sim 0.2$, while for solar-like stars it
is overestimated by up to a factor of $\sim 4 - 5$. Neglecting radial profile
measurements and using solely photometric measurements, the factor of
overestimation increases for solar-like stars up to $\sim 7 - 14$.
