No all you need is the spectral distribution, the watt and the lumens output - and some funky math as shown in the Ivo Busko page at Aquabotanic. I've made a calculator for it, and have some values calculated here:
DefBlog - PUR-efficiency list
Thanks for the link. I added it to the original article. The Ivo Busko article answers the next logical question as to what PARTICULAR bulb and therefore outside the scope here. Please PM me if you would like to see portions of the original article modified.