Water Wetter_tm is more than just a surfactant.
It also has a dye (pink!) big deal right, AND
it pushes you cooling system pH to the basic
end of the scale. This keeps corrosion from
happening. The degradation products of gycols
are acids, and this product prevents them from
starting anything nasty. Certianly phosphates
could allow for some increased acidity, but
it would prolly be minimal compared to the dose
of salts you get from WW.