Actinics are not as low in PAR as most people think. Humans eyes are not able to see that spectrum of light very well , so even though actinic bulbs may look very dull or dim , there is lots of usable spectrum. In fact actinic bulbs are very high in PUR which is probably more important then PAR.
Here are a couple of good reads on the subject.
http://www.advancedaquarist.com/2009/3/review
http://www.advancedaquarist.com/2012/10/aafeature