Comparison of means (1 continuous DV and 1 categorical IV)

I have 1 continuous dependent variable, nitrate, and 1 categorical independent variable, geology (12 categories). I want to compare the mean nitrate found in each geology type.

I have done a one-way anova in SPSS using the Hochberg and Games Howell Post Hoc tests because the data set is large and the sample sizes are unequal. I have the significance levels between the different geological types in the multiple comparison table but this table is really big and I'm finding it difficult to digest. Is there a better way of approaching this? Or am I doing this totally wrong.

I'm sorry if this may seem very basic but I have read so much conflicting information that I’m confused!

Thanks in advance for any help


Not a robit
Described analyses seem acceptable. The reporting of this many differences will be arduous and difficult to make easily interpretable by reviewers. Perhaps report means in table, but if not all differences are significant only report those that are significant or a second column width table that lists all of the pairwise differences for those that are significant. Lastly, review the literature to attempt to find some other used options.