Hello, I would like to employ Chemtax to calculated algal class contribution in periphyton, however, some problems appeared which I am not able to solve.

BACKGROUND INFO: The script is running. Concentration of pigments is entered in ugPigment/mgOrganicMatter. Initial ratios and limits are set according to Higgins et al, 2001 at the Rat01 followed by randomised ratios.

PROBLEM DESCRIPTION (see enclosed excel file):

You can clearly see there is something wrong - if you have a look at first 3 samples in list "OutR1" it gives very high cyanobacteria contribution (around 72%).

Hovewer pgments which I have chosen for determination cyanobacteria group (myxo, cantha) are not presented in those samples at all (see data sheet).

According to microscopy there should be around (Cyano = 2%, Chloro = 6%, Dia = 92%). This fits with occurance of specific pigments in the data sheet but totaly not with the results given in the OutR1 sheet.

Does anyone have some idea how to solve this problem?

Thanks a lot!

Eliška Konopáčová