Well, as I promised, I just tried the 14W grow LED array by itself over the tank that already has a 30W LED flood light + a 24W T5HO Giesemann Midday:
Observations of the pearling. Percentages are approximate of course:
All 3 lights - 100%
30W LED + 24W T5HO [Total of 54W]- 95
30W LED - 75
14W LED - 0
24W T5HO - 0
14W LED + 24W T5HO [Total of 38W] - 20
14W LED + 30W LED [Total of 44W]- 100
Ok, remember that the 14W grow light illuminates only two small swords the best (right underneath). There is enough light that spreads over the entire bottom of the tank (18"x22") but I do not know how useful it is. The two small swords stop pearling within 30 seconds of leaving only the 14W LED running. They do not pearl with the 24W T5HO by itself either. The go all out when the 30W LED is used either with the 14W or the 24W or both.
Overall I can only say that it looks like no matter if I use the 24W T5HO or the 14W LED when they are used with the 30W LED the pearling is just fine. The pearling is not fine with the 24W T5HO and the 14W LED although they have all the good wavelengths. Not sure if this means that sheer intensity is indeed more important than spectrum or that the 30W LED blue really works or its intensity is doing the trick.