Revise the biofilm fractions and find new names for biofilm compartments

The biofilm is divided into different compartments. In the Java-version, they are called BiofilmF, BiofilmN and BiofilmM. BiofilmF represent the part of the biofilm where thick biofilm and filamentous algae can grow (BaseBiofilm here). BiofilmN represent a part where just thick biofilm can grow (ThickSusceptibleBiofilm here). BiofilmM represent the micro niche where no thick biofilm and no filamentous algae can grow (MicroNicheBiofilm here). The ratio between BiofilmF and BiofilmN is set by etta (BaseFraction here, 0-1). The ratio between BiofilmF + BiofilmN and BiofilmM is set by mu (MicroNicheFraction here, 0-1).

Let's consider: etta = 0.75, mu = 0.2

In this case, BiofilmF is 60%, BiofilmN is 20%, and BiofilmM is 20% of overall biofilm.

So I think the three compartments should get better names and a clear fraction where the sum of all three is 1. Like this:

• BaseFraction = 0.6
• ThickSusceptibleFraction = 0.2
• MicroNicheFration = 0.2

The problem is, that several calculations, especially considering capacities, have to be changed as well. Check the systems biofilm_growth, eutrophication, grazing and drift.