I would like to determine if using multiple comparisons test would be appropriate for my data. I used the Kruskal-Wallis test to determine if there were differences in mean inhibition among 17$17$ different groups. The analysis revealed that there were significant differences and now I would like to use a multiple comparison procedure (perhaps Dunn's since I have unequal sample sizes) to see which groups were different from the rest.
I was wondering since I have many groups (k = 17$k = 17$) would this make a multiple comparisons test have very little power or not appropriate to perform for this data set?