This is the appearance of the Phytoplankton tab of the System Coefficients dialog:
Phytoplankton is defined as the community of algae that is suspended or floating in the water column. Following is a description of the parameters associated with Phytoplankton. Refer to the main System Coefficients page for information on other categories of coefficients. To save the changes made when closing this dialog, click OK. To ignore changes, click Cancel.
The spreadsheet contains coefficients for each of the phytoplankton communities. The coefficients apply to all rivers within the watershed.
Nitrogen Half Saturation is the growth rate half-saturation constant for nitrogen for the algae. (0.01 – 0.03 mg/l)
Phosphorus Half Saturation is the growth rate half-saturation constant for phosphorus for the algae. (0.001 – 0.005 mg/l)
Silica Half Saturation is the growth rate half-saturation constant for silica for the algae. (0.0 – 0.10 mg/l, non-zero for diatoms)
Light Saturation is the saturating light intensity for the algae. (50 – 200 W / m2)
Lower Growth Temp is the temperature below which the algae can not grow. (0 – 15 degrees C)
Upper Growth Temp is the temperature above which the algae can not grow. (25 – 45 degrees C)
Optimum Growth Temp is the temperature at which the algae’s growth is maximized. The maximum growth rate decreases linearly from this temperature to the Lower and Upper Temperature Limits. (20 – 35 degrees C)
Growth, respiration, mortality, and settling rates are set in the River Reaction Coefficients dialog.