I am stepping trying to perform a couple of statistical tests to determine significance from categorical variables (e.g., treatment, station)
the experiment is microcosms with freshwater amended 2 different types of oil to measure degradation. 3 different stations with 3 different salinities and temperatures were set up and in triplicate bottles. subsampling for degradation data happened every 2 days and the experiment ran 14 days total. having the hydrocarbon data, we see slight decrease in oil concentration but I am wondering how to determine if this decrease over time is significant? and if decreases between each time point is significant?
based on previous literature I think I should be using ANOVA or 2 way t-test? however those tests do not seem to take time into consideration?
thank you for your help.