WD periods as a function of mass. The data points are from Kawaler (2015) and Hermes et al. (2017). The black diamonds are the DAVs, the black crosses are other pulsating white dwarfs. All coloured symbols are our predicted WD periods: the sphere and hexagon are the models without ν_add; the triangles are the models with different values of ν_add; the square is the model that excludes ν_add at the end of core helium burning; and the star, cross, and plus signs are the models that exclude ν_add at different times during the core helium burning phase.