# Total solute concentrations

The alkalinity solvers need to know the total concentrations of chemical species involved in pH-dependent equilibria in seawater. These are collated in a dict called concTotals, to conveniently pass this information into the solver functions. The dict can be generated using the function of the same name in the concentrations module, or you can assemble your own manually.

## concTotals: dict of concentrations

Assemble a dict of concentrations as required by other Calkulate functions.

Syntax:

concTotals = calk.concentrations.concTotals(pSal, totalCarbonate=0,
totalPhosphate=0, totalSilicate=0, totalAmmonia=0, totalH2Sulfide=0,
WhichKs=10, WhoseTB=2)


The output concTotals dict contains the following variables:

Defined by inputs to the concTotals function:

• C - totalCarbonate.
• P - totalPhosphate.
• Si - totalSilicate.
• NH3 - totalAmmonia.
• H2S - totalH2Sulfide.

Estimated from input practical salinity by PyCO2SYS:

• B - total borate.
• S - total sulfate.
• F - total fluoride.

The exact functions of salinity used by PyCO2SYS to estimate these concentrations can be set using the inputs WhichKs, which is the same as the PyCO2SYS input K1K2CONSTANTS, and WhoseTB, which corresponds to the PyCO2SYS input KSO4CONSTANTS: a value of 1 for WhoseTB is the same as options 1 and 2 for KSO4CONSTANTS, while a value of 2 is the same as options 3 and 4.