Carbon uptake rates vs. irradiance (n = 3) using pHOS.

The estimated net carbon growth rate for a separate culture validation experiment at 110 μmole quanta m^-2 s^-1 is indicated by the closed square and the corresponding interpolation from the pHOS data at the same irradiance is shown in the inverted triangle (n = 6). Carbon uptake rates determined from these two approaches are not significantly different from each other (p > 0.05).